How do I position the markup text above the crescendo?
\relative c {
c4\< c c c-\markup{ "sim." } | c c c c\ff
}
One way to to it is to change the outside-staff-priority. A DynamicLineSpanner (the hairpin) has an outside-staff-priority of 250 so setting the TextScript (markup text) to anything below that will make the text appear above the hairpin.
\version "2.24.3"
\relative c {
\override TextScript.outside-staff-priority = 200
c4\< c c c-\markup{ "sim." } | c c c c\ff
}