Muun is a different beast since it does swaps in the background.
I believe that under the hood it converts anything received via lightning to a utxo.
Outside of Muun, your lighting channel is your UTXO in a multisig with your channel partner.
Whatever you send and receive is tallied up and when you close the channel you split that utxo into whatever that tally is at the end.
In short, it doesn’t matter how many lighting transactions, only your final balance matters.