Yes on reliability but debateable on the ruggability. Mint dependent for sure. But that's the whole point.
Discussion
Any custodian is ruggable, but the fact that Primal uses Strike as its wallet provider/custodian gives me MUCH more confidence that it’s less likely to be rugged than some random cashu mint. Possible? Yes. Likely? No, as Strike would have to be willing to nuke its reputation to do so.