Don’t forget fingers.
I currently have a glassie in L0, a flex in L4 and another flex in L8 with zero interference. I would feel very confident putting another flex in L1 (because it would end up 90 degrees in the field if I present my L0 glassie, rendering it unable to talk), in L7 (because index and middle fingers can be oriented 90 degrees apart and 90 degrees from the metacarpals very easily) and L10 if space allows. L9 would be an option also if my L8 wasn’t already taken, but it’s not so easy to control the ring finger independently from the middle finger.
Implants in P1 through P5 rely on distance to avoid crosstalk because they’re all roughly in the same plane. P0 isolates P1-5 implants because the wrist puts them in another plane, and finger joints give you yet further options to select which implant ends up flat against the reader and which end up vertical.
If your installer is good enough to do finger installs that is. Mine is, and my next one is definitely going in a finger. It’s just so damn convenient.