That's not the whole story. The first swap in, or back out it can be horrendously expensive. However once in, it's just regular lightning. I just sent 500 sats from MUUN to mutiny wallet, 1 sat fee. Instant RX over lightning.

I use muun to aggregate (incoming only) onchain and lightning sats. Once I have a large enough number of sats, I send it onchain to my cold storage or mixer in one transaction to consolidate my utxos. I try not to send lightning payments out using muun because their implementation of submarine swaps can cause high fees even when using lightning. Each transaction OUT requires both a lightning and onchain transaction. Lightning transactions in are fine because the sender pays the normal lightning fees. Muun is great for aggregating all those little zaps into one big(ger) onchain utxo.

Lol, I'm a dumbass and covered the fee on my screenshot. It was 1 sat. 501 total out.