Banning Biggs is silly. Biggs by no means is unbalanced in any way whatsoever. Any buff that is applied could simply have a restriction to allowing Biggs to equip if the designers thought it was to powerful for him.
And the problem with the X-wing isn't that it's bad, the problem with the X-wing is that it's mediocre in a game where if you don't take the most optimizable list possible, you are at a disadvantage.
It would be easy enough to make a title PS-restricted (Royal Guard TIE and Virago both are). PS6+ requires biggs to equip R2-D6 and Adaptability (increasing the cost of the card by a point plus his astromech slot - stopping him taking R4-D6), PS7+ requires biggs to equip R2-D6 and Veteran Instincts (increasing the cost of the card by two points plus his astromech slot), PS8+ stops him taking it at all.
Since the pilots people most bemoan not being able to use are Luke, Wedge & Wes, PS8+ would make sense for a "Rebellion Ace" or "Rogue Leader" title card. Garven Dreis would still be able to take it with R2-D6 and Veteran Instincts, but in his case this is actually a good pairing with his ability (since he wants to shoot and spend his focus token early) as opposed to just an annoying extra cost for Biggs, whilst Porkins can get by with just putting Adaptability in his Elite upgrade.
Secondly, a putative X-wing buff is only a massive problem for biggs if it's making him tougher. Since he is almost inevitably the first guy killed, a slight increase in firepower, or manoeuvrability, is less of an issue.
Edited by Magnus Grendel