I'd steer clear of a Catch-less Physical Immunity, but for Recovery, Toughness, or a combination of the two, at any level, I'd allow a character to be Catch-less for a one-time cost of 1/4 of all refresh spent on affected powers, rounded up (affecting one (or both) Inhuman power(s) costs 1 additional refresh, affecting both mythic powers costs 3 additional refresh).