It's a bit of a radical suggestion, but one option would be to change how the multipliers stack. If you had them each multiply the base value rather than the total value, and add a different benefit to having multipliers from multiple sources (such as a flat x2 for each different multiplier source), then that would probably resolve the issue on its own; with the way the trauma scaling currently works, they'd likely level out at a much more manageable number of capture rounds, while the player would still be rewarded for getting those multipliers as high as they can.
Plus, this would also address the (minor and cosmetic) issue of how the game runs out of new descriptions for trauma at high levels
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But while you're here... I have a minor suggestion I'd like to offer! It's nothing important, but I hope it's interesting.
Locations. Currently, you always "ambush a neighborhood on [name's] patrol route"; this is fine as-is, but there's more potential here, isn't there? After all, you're the one setting the terms of the engagement; why not use it to your advantage? The genre has a long history of the villains drawing the heroine into traps, and I think it would be nice to lay some of our own.
My suggestion is to include a branch of research into various places to stage your battles for minor advantages, at the expense of a point of Evil Energy - perhaps attacking a construction site or factory starts them out with a level of Injury circumstances, or attacking a gang headquarters starts them off with a level of Hate. Maybe going after their fanclub starts them with a level of Shame trauma, or tricking them into some kind of lair gives them Fear.
We could also do some more complicated things with this idea - perhaps drawing them out to a remote location ensures that reinforcements are delayed by a turn or two, or attacking a particularly crowded area slows evacuation efforts. Or perhaps attacking a studio gives a bonus to Shame/Exposure attacks (easy broadcasting) but a penalty to Fear/Hate attacks (a desire to maintain composure) for the first few rounds (when the location is presumably destroyed in the chaos).
I think there are a lot of ways one could play around with the idea.