Some upgrade card ideas my group and I have tossed around
Bombing Scope (0)
Modification
"When you roll damage dice for a <bomb> template that you dropped, you may change one <focus> result into a <hit> or <critical> result"
Munitions Astromech (0)
X-wing Only
"If you equip a <torpedo> upgrade reduce its squad point cost by 2 (minimum 0)"
Advanced Solar Arrays (1)
Modification TIE Only
Action: Gain one shield token, even if this would increase your shield value above its maximum value. During the end phase, lose 1 shield token.
The bombing scope would help out K-wings, Firesprays, Punishers and Bombers by making low PS mine layers scarier.
Munitions astromech would give the X-wing a reason to take torpedoes and it would provide a 0 point astromech to discard for IA once your torp is off.
Advanced Solar Arrays is basically designed to allow the mediocre/terrible pilots from Imperial Aces to get a PtL like effect without the EPT slot (by taking Advanced solar arrays and Experimental Interface)