palm side is good for padding, good absorption in the area.
It being an xg3 though i wouldn’t recommend it, size, glass, higher potential of impact if you put your hands out to stop a fall or crush if pressing something heavy, depending on where exactly in -P0 it ends up.
Is it an xg3v1 or v2? If it’s a v2 (since the v1 is no longer sold) don’t bother putting it there anyway, -P0 is best for sensing because of nerves and the xg3v2 is primarily a lifting magnet with less sensing.
I have personally put a lot of implants in myself in some very very silly positions and would not go for palm-side P0 for a glass implant, my titans are in -P0 on both hands.
Depending on how big your hands are and how much real estate you have, the side of the middle finger, on the bottom knuckle, may serve you well, would be decent for sensing and would be coushened between the fingers.
YMMV.