Alright, having played a game with the Champion and heard other players feedback, I think the bonus the AI gets need to be relative to the number of nebulas completed.
My reasons for this are that the flat 20% bonus is one of the reason I lost my last game.
Because I got pinned and was scrambling to stay alive I was only able to complete 3 nebula scenarios and so never got larger then the destroyer hull.
Compared to people talking about their champion soloing high mark systems (or even a homeworld), mine was lucky to survive raiding a guardpost in a Mk III system.
So I was eating these waves that were 20% bigger when my champion really was not worth 20% in the slightest.
So maybe the AI starts with a 3% bonues, that goes up by 3% for every nebula completed? That would give it the 20% bonus after the 6th nebula which means you should have the cruiser hull and is when the champion really starts to shine.
Keeping in mind that I played this game on 10/10, here are the numbers that prompted me to post this suggestion:
Last CPA of the game: 10,000 units, so 8,000 units base + 2,000 units from the Champion bonus.
Last wave of the game: 5,200 units, so 4,300 units base + 900 units from the Champion bonus.
My champion on a destroyer hull was simply not that powerful, not even close. Now, it was 10/10 so I expect punishing, but even the bonus part normal wave at 900 units would simply blow past my champion in a single salvo, I expect my champion to at least slow down the bonus ships the AI is getting due to it's presence.
D.