Interesting project. I am not having performance problems with the crowd controller, however it has some limitation, which we need to overcome for our project in the future. Would be interested in your plugin, if it does not have these limitations. Especially working with multiple capsule sizes. Dont know if you are aware of it, but unreals detour crowd controller can only handle one capsule size. Pawns with different capsule size, which should pick a different nav agent, can’t move at all, because detour crowd controller only works with one nav agent.
Also for performance checks, always make a shipping or test build for that. You will get very different results than in editor.