BlueWallet is custodial unless you've connected it to your own lndhub instance on your own node. Muun is non-custodial in that all your funds are on-chain, but it isnt a lightning node, and in that case it isn't really a lightning wallet, so there is no pubkey associated with it to use lnurl-auth with. Muun is an on-chain wallet that interacts with the lightning network via submarine swaps. This is very inefficient and isn't sustainable. They make up for this by charging very high fees, especially to those sending funds to a Muun wallet over LN. All funds sent to a Muun wallet pass through their node called "magnetron" which charges at least 1500ppm fees which is insane.

Blixt Wallet is probably the most transparent and flexible lightning wallet out there right now, and it's getting better with every update.