"On a successful check, the wounded character gains heal one Wound."

"Treat each wound separately making only a one attempt ... Under no circumstances does the Treat Wounds check heal more damage than the treated wound."

Exception to the Rule of Three? I didn't see any other instruction to track damage from each hit separately, 5E players would probably just total it all up. Maybe mention this back in the Damage section on page 35?

"Critical Success: The character regains Heal two Wounds."

This is a place where you're asking people to track many separate pieces of data over time. At your table, how do you indicate a wound has or has not been treated yet with Treat Wounds? Color? Checkmark? Circle it? Make a recommendation in the rule text.