i don’t think so, bc all the “resurrection” spells that coustas attempted were unsuccessful, if coustas cast it on jujy’s master, hieheart, he wouldve probably ended up like dagda, stuck in a loop of reversing time and replaying his death until coco and the others figured out a better way with the time reversal operating table.
so long winded explanation on what i think is most likely happening here. so the aftermath of the curtain leech arc, when hieheart and jujy were fleeing, he gets attacked by the leech while protecting her, then they find the alleyway full of all the people that coustas “resurrected.” coustas throws hieheart into the leeches and that lowkey traumatizes jujy. remember the theme of what’s wrong or right when it comes to magic, why healing magic was banned and everything? jujy wanted very badly to do anything to save her master, however he was prepared to die. i’m sure he thinking along the lines of not wanting to potentially endanger jujy by making her use forbidden magic. hieheart was also rigid about all brimhats being bad, so that kinda pissed off coustas, bc coustas needed validation that what he was doing wasn’t wrong. in the end, we could see jujy asking coustas to cast that spell on hieheart to temporarily save him, so she made her choice, that forbidden magic was the answer. so essentially, hieheart got forbidden magic carved into him to reverse the injury, then got taken to the medical spire/any hospital to help treat the wounds when they would inevitably reappear. that would align with what the manga showed, all the unknowings who have been saved by coustas, being granted permission to go to the medical spire for time reversal treatment.
so i think the problem now is that jujy feels guilty for choosing forbidden magic to save her master, even though she wanted to do anything to help him, and hieheart thinks he is an unworthy instructor for having caused her so much pain and carrying the burden of making the choice to let him die or seek forbidden magic. i think these two are supposed to act as a foil or comparison to qifrey and coco, as both have issues but strong bonds as student and master.

Oh no could it be the master is already dead?