Hi Alain,
the Stickup is smaller than the "Block" modules (ACTV-2 and PASV-4). So you need a sort of adapter and/or new holes in your Stick, because the screw positions are different.
Rodrigo Serrão has a Grand Stick he changed from ACTV-2 to a Stickup. You can find it on YT in different videos, like here:
https://youtu.be/VyWag3ez42M