I am trying to make this small decorative sink by Criquette functional, and more specifically want it to be usable on a single tile, to fit in tiny bathrooms.

I started by cloning the cheap BG sink and creating a new object as usual.
I managed to edit the routing slot for the Sim to stand closer to the sink on the same tile, and not clip through the wall. However, their arms now clip through the wall behind the sink, when they reach for the knobs to open/close the faucet. There is also some more minor clipping during the hand washing animation itself, but I think it's less distracting.
(please ignore the water surface sticking out, I managed to fix that after taking the screenshots)

I thought there was a way to edit the joint coordinates in the CRES to change the placement of the Sim's hand (I did something similar while working on my kettles to adjust where they grab the handle), however it does not seem to work in this case and the animations look unchanged in game.

Is there a way to change that? Am I trying to edit the wrong thing?