Submarine swaps don't provide any additional privacy than what's already available in the Lightning Network and Bitcoin blockchain. So you can increase the privacy of your Lightning network by routing through multiple channels such as onion routing.
Right, but the Swap process enables on-chain BTC to become off-chain BTC, wouldn't this action get rid of traces ? Furthermore, I swap the off-chain coins back to on-chain coins again before spending it. Sounds that the BTC got mixed enough
Regarding the 'routing' you mentioned, I use Muun wallet, how do I route through multiple channels like onion routing ?