What happens? If a prox mine is half off the map, does it stay? A bomb could still reach a damage through on something near the board edge. A prox mine that was outside the play area but near the mat could still trigger on a ship that did a hard turn off the map but landed back on it.

Same with partially off the map bombs. What happens?

There was something in one of the FAQ's if I remember correctly...

A bomb that detonates right away, like a proton bomb or Ion still goes off, but the AoE is only counts for the part that would be on the table.

I think for Prox or Conner nets, the same would apply. If part of the token is on the table then only the part that's on the table counts.

Agreed, some portion has to be in the play area.

The FAQ is worded as follows: