muun wallet rely on muun channels, hence they are custodian. its very convenient as you dont need to run your own node. no opening channel fee needed as you kinda share the channel with every muun user. however, they kinda control the channel fee, making it more expensive than a regular full custodian wallet like WoS

however, the wallet are multisig.

so if muun is doing their hanky panky, you can force close the channel.