Toggle different math fonts with XeLaTeX

My goal is to use a sans serif math font in all figures and I found several approaches with my favourite being the use of mathversion and the unicode-math package to change between different math fonts.
However, I am not able to switch between fonts due to the warning

Package fontspec Warning: Font "Latin Modern Math" does not contain requested
(fontspec) Script "Math".

that repeats for all fonts I import with a [version=] parameter. However, I can change the math font for the whole document.

So my question: What am I doing wrong? I basically copied my code from another answer (will add the link when I find it again).

My mwe for testing is

documentclass[authoryear,preprint,5p,11pt]{scrartcl}
usepackage{amsmath}
usepackage{pgfplots}

usepackage{fontspec}
usepackage[]{unicode-math}
defaultfontfeatures{ Scale=MatchLowercase, Ligatures=TeX }
setmathfont{XITS Math}
setmathfont{Latin Modern Math}[version=lm]
setmathfont{TeX Gyre Pagella Math}[version=pagella]

begin{document}
This is some text.

And a figure with maths elements
begin{figure}[ht]
  % mathversion{sansmath}
 begin{pgfpicture}
 pgftext[x=0.691229in,y=0.540666in,,top]{sffamilyselectfont 125}%
 pgftext[x=0.354158in,y=0.432447in,left,base]{sffamilyselectfont (displaystyle frac{-pi}{2})}%
 pgftext[x=1.054158in,y=0.432447in,left,base]{sffamilyselectfont (displaystyle 10^{3123x} cdot 12389)}%
 end{pgfpicture}
end{figure}
and a formula
[ frac{pi}{2.42132}= beta]
 and some math in another font
mathversion{lm}
[ frac{pi}{2.42132}= beta]
 and yet another one
mathversion{pagella}
 [frac{123456} {some text}]

end{document}

The full logfile is here: https://pastebin.com/kS3quC7A

documentclass{article}
usepackage{amsmath}

usepackage{fontspec}
usepackage[]{unicode-math}

setsansfont{GFSNeohellenic}[
  Extension=.otf,
  UprightFont=*,
  ItalicFont=*It,
  BoldFont=*Bold,
  BoldItalicFont=*BoldIt,
]
setmathfont{Latin Modern Math}
setmathfont{GFSNeohellenicMath.otf}[version=sansmath]

begin{document}
This is some text.

And a figure with maths elements

begin{figure}[ht]
centering
sffamilymathversion{sansmath}

[
125+frac{-pi}{2}+10^{3123x} cdot 12389+sin3
]

caption{Whatever}

end{figure}

and a formula
[ frac{pi}{2.42132}= beta]

end{document}