Like Ohrime's rejection skill? So your saying that karma seals also have s/t jutsu. Im not ruling it out but what Jigen did compared to Boruto healing his hand is worlds apart. I'll keep it mind tho. On second thought why couldn't Kawaki regen his arm after saving Delta?
Kawaki probably doesn't have the time manipulation skill to his Karma. I'm thinking that the reason that Boruto and Jigen have it is because they killed an Otsutsuki to get their karma seals (I am speculating that Jigen killed some Otsutsuki like perhaps Urashiki to get his).
Meanwhile, Kawaki's karma seal was just a hand-me-down from Jigen. Kawaki didn't kill an Otsutsuki.
There is some potential evidence that karma users who kill an Otsutsuki get special abilities that other karma users don't get. Namely: When Boruto's hand healed, we (and Boruto himself) saw an image of Momoshiki pop up (that nobody else saw).
Meanwhile, Kawaki has shown no such karma healing power or time reversal.