Hi Julius,
I do not get your point: I've created a Standard Transaction variant for SU3 in SHD0.
Now I happily can switch between tabs in SU3 always getting the restricted screen.
Caution: you cannot create variants for SU0 / SU50, SU1 /SU51, SU2 / SU52 as these transactions are already Variant Transactions. You have to refer to SU3.
Kind regards
Frank