Is it possible to mod the aircraft AI to produce one that is more fun to dogfight against?

[Rolds]

Could their detection and performance be modified? Or their tactics?

[Art-J]

Performance? Probably, by editing relevant .lua files in coremods folder. Here's example of modding done on AI MiG-15:

Detection angles, ranges and tactics? Highly unlikely. These must be hardcoded, otherwise we wouldn't have to wait for ED tweaks to AI flight and ground units behaviour, which they started improving last year.

[intruder11]

You can also add extra weight to the AI via lua scripting (setUnitInternalCargo trigger action) to reduce their effective performance.