Thanks! The percentage rules don't depend on the plan as it reads the 5-hour and weekly percentages Claude Code reports, so asking at 80% and refusing at 95% works the same on Pro or Max 20x. Same for the burn rule (20 points of the 5-hour window in 10 minutes).
The ones that depend on the plan are the absolute numbers: 4 agents running at once, 12 agent starts per 10 minutes, 10M subagent tokens per 10 minutes, and the 500k context before it asks to compact. I tuned them on my own Max 5x, so on Pro they are probably too loose. You can change all of them with env vars (AGENT_GUARD_*), but presets per plan is a good idea, I'll look into it.