How can I make this Lua script more reliable?

So I've been trying to make my Lua scripts in LogitechGHUB better so that they don't skip a few shots or stop working all of a sudden for a couple of seconds, originally I made this code but no matter what I did it still failed at random moments

EnablePrimaryMouseButtonEvents(true);
function OnEvent(event,arg)
 if IsKeyLockOn(LockKey)then
            if IsMouseButtonPressed(RC) then 
                repeat 
                           if IsMouseButtonPressed(LC) then 
             repeat                 
                     MoveMouseRelative(0,11)
                     if (coun2<2 and IsMouseButtonPressed(LC))
                     then 
                         MoveMouseRelative(3,13)
                         end
                     if (coun2>10 and coun2<25 and IsMouseButtonPressed(LC))
                     then 
                         MoveMouseRelative(0,1)
                         end
                     if (coun2>35 and coun2<55 and IsMouseButtonPressed(LC))
                     then 
                         MoveMouseRelative(1,0)
                         end
                      if (coun2>65 and coun2<75 and IsMouseButtonPressed(LC))
                     then 
                         MoveMouseRelative(1,1)
                         end
                     if (coun2>85 and IsMouseButtonPressed(LC))
                     then 
                         MoveMouseRelative(1,1)
                         end    
                     Sleep(1)
                     coun2 = coun2+1
             until not IsMouseButtonPressed(LC)
             coun2=0
         end  

                 until not IsMouseButtonPressed(RC)
                end
end
end
LockKey="numlock"                       
coun2 = 0
LC=1                                        
RC=3                                

I changed the idea of using counters to make it more customizable, for loops like this

EnablePrimaryMouseButtonEvents(true)

function OnEvent(event, arg)

   if event == "MOUSE_BUTTON_PRESSED" and arg == 1 and IsMouseButtonPressed(3) and IsKeyLockOn("numlock") then
      for i = 1, 2 do
         MoveMouseRelative(3,20)
         Sleep(1)
         if not IsMouseButtonPressed(1) then return end
      end
      
      for i = 1, 135 do
         MoveMouseRelative(1,12)
         Sleep(1)
         if not IsMouseButtonPressed(1) then return end
      end
end
end                             

Which did in fact make it more consistent as long as I didn't use too many for loops, but it still occasionally stops moving the mouse for random periods of time. I tried changing the Sleep() functions for FastSleep() that I saw another user recommending, but it remained the same just faster. Is there a way of making the script less bound to fail or like something I'm not understanding that messes the code? Or should I simply try a different coding language?

Try

local LockKey = "numlock"                       

local moves = {  -- dx/msec, dy/msec, msec
   {0.3, 2.0, 30},
   {0.0, 1.1, 100},
   {0.0, 1.2, 150},
   {0.0, 1.1, 100},
   {0.1, 1.1, 200},
   {0.0, 1.1, 100},
   {0.1, 1.2, 100},
   {0.0, 1.1, 100},
   {0.1, 1.2, math.huge},
}

local function get_distance(t)
   local x, y = 0, 0
   for _, move in ipairs(moves) do
      local vx, vy, mt = move[1], move[2], move[3]
      if t < mt then
         mt = t
      end
      x, y = x + vx*mt, y + vy*mt
      t = t - mt
      if t <= 0 then break end
   end
   return math.floor(x), math.floor(y)
end

function OnEvent(event, arg)
   if event == "PROFILE_ACTIVATED" then
      EnablePrimaryMouseButtonEvents(true)
   elseif event == "MOUSE_BUTTON_PRESSED" and arg == 1 
      and IsMouseButtonPressed(3) and IsKeyLockOn(LockKey) 
   then
      local t0 = GetRunningTime()
      local t = t0
      repeat
         Sleep(10)
         local oldx, oldy = get_distance(t - t0)
         t = GetRunningTime()
         local newx, newy = get_distance(t - t0)
         MoveMouseRelative(newx - oldx, newy - oldy)
      until not IsMouseButtonPressed(1)
   end
end