Aside from what Theo pointed out, that jev doesn’t have the reasoning trace as context for why a tool was called, models are trained on their compaction strategy very deeply.
Even if your idea is good, it will underperform vs what it was trained to use well.
I would not dismiss the idea of using Jev for compaction at all. First of all because most harnesses need some pruning on compaction anyways for cost reasons which Jev might help with. I can see this being quite interesting.