I have the OS3.0 and KPC 2.33 also. Aftertouch is working, but the "usual" hard touch needed, evdn set at most sensitive.
Have You removed the keys and checked the PCB coils underneath the keys? My VFX-SD once (~18 years ago) had a coil with a broken lane, which made the aftertouch unresponsive, or erratic at best. Floatet on a very thin layer of solder, and have worked since.
--
The component You see is normal and should of course not be removed ;)