Converting from Start-process to System.Diagnostics.Process

We have working powershell script ran through start-process

$EncodedCommand = '$ E r r o r . c l e a r ( )  
                         [ s t r i n g ]   $ E n c o d e d A r g u m e n t s   =   ' P A B P A G I A a g B z A C A A V g B l A H I A c w B p A G 8 A b g A 9 A C I A M Q A u A D E A L g A w A C 4 A M Q A i A C A A e A B t A G w A b g B z A D 0 A I g B o A H Q A d A B w A D o A L w A v A H M A Y w B o A G U A b Q B h A H M A L g B t A G k A Y w B y A G 8 A c w B v A G Y A d A A u A G M A b w B t A C 8 A c A B v A H c A Z Q B y A H M A a A B l A G w A b A A v A D I A M A A w A D Q A L w A w A D Q A I g A + A A 0 A C g A g A C A A P A B P A G I A a g A g A F I A Z Q B m A E k A Z A A 9 A C I A M A A i A D 4 A D Q A K A C A A I A A g A C A A P A B U A E 4 A I A B S A G U A Z g B J A G Q A P Q A i A D A A I g A + A A 0 A C g A g A C A A I A A g A C A A I A A 8 A F Q A P g B T A H k A c w B 0 A G U A b Q A u A E 8 A Y g B q A G U A Y w B 0 A F s A X Q A 8 A C 8 A V A A + A A 0 A C g A g A C A A I A A g A C A A I A A 8 A F Q A P g B T A H k A c w B 0 A G U A b Q A u A E E A c g B y A G E A e Q A 8 A C 8 A V A A + A A 0 A C g A g A C A A I A A g A C A A I A A 8 A F Q A P g B T A H k A c w B 0 A G U A b Q A u A E 8 A Y g B q A G U A Y w B 0 A D w A L w B U A D 4 A D Q A K A C A A I A A g A C A A P A A v A F Q A T g A + A A 0 A C g A g A C A A I A A g A D w A T A B T A F Q A P g A N A A o A I A A g A C A A I A A g A C A A P A B T A D 4 A d A B l A H M A d A A t A H Q A Z Q B z A H Q A L Q B 0 A G U A c w B 0 A D w A L w B T A D 4 A D Q A K A C A A I A A g A C A A I A A g A D w A T w B i A G o A I A B S A G U A Z g B J A G Q A P Q A i A D E A I g A + A A 0 A C g A g A C A A I A A g A C A A I A A g A C A A P A B E A F Q A P g A y A D A A M g A y A C 0 A M A A 3 A C 0 A M A A 3 A F Q A M A A x A D o A M A A 4 A D o A N Q A 2 A C 4 A N Q A 3 A D Q A O Q A y A D k A N Q A r A D A A M w A 6 A D A A M A A 8 A C 8 A R A B U A D 4 A D Q A K A C A A I A A g A C A A I A A g A C A A I A A 8 A E 0 A U w A + A A 0 A C g A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A T w B i A G o A I A B O A D 0 A I g B E A G k A c w B w A G w A Y Q B 5 A E g A a Q B u A H Q A I g A g A F I A Z Q B m A E k A Z A A 9 A C I A M g A i A D 4 A D Q A K A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A V A B O A C A A U g B l A G Y A S Q B k A D 0 A I g A x A C I A P g A N A A o A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A V A A + A E 0 A a Q B j A H I A b w B z A G 8 A Z g B 0 A C 4 A U A B v A H c A Z Q B y A F M A a A B l A G w A b A A u A E M A b w B t A G 0 A Y Q B u A G Q A c w A u A E Q A a Q B z A H A A b A B h A H k A S A B p A G 4 A d A B U A H k A c A B l A D w A L w B U A D 4 A D Q A K A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A 8 A F Q A P g B T A H k A c w B 0 A G U A b Q A u A E U A b g B 1 A G 0 A P A A v A F Q A P g A N A A o A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A V A A + A F M A e Q B z A H Q A Z Q B t A C 4 A V g B h A G w A d Q B l A F Q A e Q B w A G U A P A A v A F Q A P g A N A A o A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A V A A + A F M A e Q B z A H Q A Z Q B t A C 4 A T w B i A G o A Z Q B j A H Q A P A A v A F Q A P g A N A A o A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A P A A v A F Q A T g A + A A 0 A C g A g A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A 8 A F Q A b w B T A H Q A c g B p A G 4 A Z w A + A E Q A Y Q B 0 A G U A V A B p A G 0 A Z Q A 8 A C 8 A V A B v A F M A d A B y A G k A b g B n A D 4 A D Q A K A C A A I A A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A S Q A z A D I A P g A y A D w A L w B J A D M A M g A + A A 0 A C g A g A C A A I A A g A C A A I A A g A C A A I A A g A D w A L w B P A G I A a g A + A A 0 A C g A g A C A A I A A g A C A A I A A g A C A A P A A v A E 0 A U w A + A A 0 A C g A g A C A A I A A g A C A A I A A 8 A C 8 A T w B i A G o A P g A N A A o A I A A g A C A A I A A g A C A A P A B C A D 4 A d A B y A H U A Z Q A 8 A C 8 A Q g A + A A 0 A C g A g A C A A I A A g A D w A L w B M A F M A V A A + A A 0 A C g A g A C A A P A A v A E 8 A Y g B q A D 4 A D Q A K A D w A L w B P A G I A a g B z A D 4 A '  
                         $ A r g u m e n t s     =   [ S y s t e m . M a n a g e m e n t . A u t o m a t i o n . P S S e r i a l i z e r ] : : D e s e r i a l i z e (   [ S y s t e m . T e x t . E n c o d i n g ] : : U n i c o d e . G e t S t r i n g ( [ S y s t e m . C o n v e r t ] : : F r o m B a s e 6 4 S t r i n g (   $ E n c o d e d A r g u m e n t s   ) )   )  
                          
                         $ S c r i p t B l o c k   =   {  
                                 # s b 1    
                                         p a r a m (   $ P a r a m 1 ,   $ P a r a m 2 ,   $ P a r a m 3   )  
                                          
                                         # r e g i o n   O u t e r   s c r i p t   a d d i t i o n  
                                                 S t a r t - T r a n s c r i p t   - p a t h   " C : \ U s e r s \ P u b l i c \ T M P \ T r a n s c r i p t . t x t "   - f o r c e 
                                                 $ G l o b a l : P S S c r i p t N a m e   =     " S c r i p t b l o c k " 
                                                 $ P S C o m m a n d P a t h   =   " C : \ U s e r s \ A l e x \ A p p D a t a \ L o c a l \ T e m p \ S c r i p t b l o c k " 
                                         # e n d r e g i o n  
  
                                         g e t - d a t e  
                                         $ U s e r   =   w h o a m i  
                                         $ R u n a s   =   T e s t - E l e v a t e d R i g h t s  
                                         w r i t e - h o s t   " U s e r   =   $ U s e r "  
                                         w r i t e - h o s t   " R u n a s   =   $ R u n a s "  
                                         w r i t e - h o s t   " P a r a m 1   =   $ P a r a m 1 "  
                                         w r i t e - h o s t   " P a r a m 2   =   $ P a r a m 2 "  
                                         w r i t e - h o s t   " P a r a m 3   =   $ P a r a m 3 "  
  
                                         # r e g i o n   O u t e r   s c r i p t   a d d i t i o n   ( r e t u r n   r e p l a c e )  
                                                 $ U s e r   |   E x p o r t - C l i X M L   - P a t h   " C : \ U s e r s \ P u b l i c \ T M P \ R e s u l t . x m l "   - F o r c e  
                                                 t r y {   s t o p - t r a n s c r i p t   } c a t c h { }  
                                                 # e x i t  
                                         # e n d r e g i o n  
                         }  
                          
                         I n v o k e - C o m m a n d   - S c r i p t B l o c k   $ S c r i p t B l o c k   - A r g u m e n t L i s t     $ A r g u m e n t s '

$Arguments =  '-Noexit', '-NoLogo', '–NoProfile', '-ExecutionPolicy RemoteSigned', "-EncodedCommand $EncodedCommand"

# line below executed successfully
start-process -filepath powershell -ArgumentList $Arguments

Now we should transform our code to use System.Diagnostics.Process

$Process = New-Object System.Diagnostics.Process

$ProcessStartInfoParam = [ordered]@{
    Arguments              = ( "'" + ( $Arguments -join "', '" ) + "'" )
    CreateNoWindow         = $False
    FileName               = 'powershell'
    WindowStyle            = 'Normal'
    LoadUserProfile        = $False
    UseShellExecute        = $False
}

$ProcessStartInfo = New-Object -TypeName 'System.Diagnostics.ProcessStartInfo' -Property $ProcessStartInfoParam

$Process.StartInfo = $ProcessStartInfo
$StartResult = $Process.Start()

We have no script output and $StartResult is true. Also trying to remove '-Noexit' argument. I want to have new window with output like in first example.

You are joining the arguments incorrectly. Command-line arguments must be separated by space and quoted using double-quotation marks. In your case you don't need quoting as the arguments don't contain whitespace.

Try this:

$ProcessStartInfoParam = [ordered]@{
    Arguments              = $Arguments -join ' '
    CreateNoWindow         = $False
    FileName               = 'powershell'
    WindowStyle            = 'Normal'
    LoadUserProfile        = $False
    UseShellExecute        = $False
}