I have a NeXT there in my right hand.
I have two Titans to install, one in each hand.
So,
P0 is unavailble due to prior install.
I have eliminated the fingertips due to my work and / or metal shavings.
I have also eliminated the knife edge of my hand, mostly just for the shavings.
That doesn’t leave a whole lot of real estate. Back side of the palm seems like the most likely area for keeping it clean from shavings, with having it in the valley between the metacarpals seems to be the most protected location. The middle position seems to have the most space available, assuming there’s not something important running through there like a major nerve or tendons, or something else.