Federation Commander

From reading the rules I understand proximity photons were removed from the game. Was there a specific reason for that? Would it break the game to use proximity photon rules?

Maybe I'm wrong, but I don't remember proximity photons ever being part of Federation Commander.

There are a lot of rules in SFB that didn't make the translation to Federation Commander. Proximity fuses on photons is one. So is DERFACS for disrupters. These were intentional decisions, all focused on making sure Federation Commander stays as streamlined as possible.

Giving the Fed that would require giving other empires other things, complicating the game while returning balance to the original point. Better to keep the game simple and streamlined and balanced.