Pilots with high piloting skill + maneuverability system modules can reach a pretty high number; I'm quite sure I've seen 400+ rating towards the endgame (most skills maxed, high end ships), and I don't normally use maneuverability modules either.

What's the current base highest maneuverability value for non-modded SW3 ships, 245? I think you can safely push it to 300+, but 450 sounds very high. Capital ships shouldn't be too agile but that's just my opinion Good luck.