Untested and might not work! The S21+ ROM (t2s) is a first test by me, the other are from those sources:
Look at xda forum for install instructions.
S21+
iode-6.0-20250204-t2s.zip
S21 Ultra
iode-6.0-20250204-p3s.zip
S21 FE
ode-6.0-20250204-r9s.zip