When PC rests overnight, they make Reslience check and convert critical to normal wound if at least as many successes as value rolled.
I think it's clear that's one critical of the number of successes rolled. E.G., PC has two critical wounds each severity 2 , rolls 2 successes. That means choose which one to convert to normal wound not heal all severity 2 criticals.
What if they rolled 4 successes?
Is the rule essentially, "you only recover one critical each night no matter how well you roll", or in this case can your say "2 successes cures first one and 2 more cure the 2nd one"?
Rob