I noticed that "Sector_SetRotation ( )" function does not works when using on a linedef (like "Sector_Alignment" [slope], "Sector_Contents" or "3DFloor").
That only works when called from an ACS script.
I didn't tested on (G)zDoom so i don't know if thats a engine issue, or that is designed to be called only from a ACS script.
If this is the case, could you set this function "calleable" as a linedef action, same as from any ACS?
This happes too when using "Sector_CeilingAlignmentToLine ( )" and "Sector_FloorAlignmentToLine ( )". They only works when called from an ACS, not when called from a linedef action itself.
Instead, I remember when i was mapping for GzDoom, that, at least, "Sector_CeilingAlignmentToLine ( )" and "Sector_FloorAlignmentToLine ( )" worked from the linedef action.
I forget, but the topic tittle is [1.26+] because this happens on 1.26, 1.29 and 1.30.