This comment, but I'm mostly talking about recieving funds online. A monero user wouldn't store any funds in Lightning, they simply swap what they recieve into Monero or swap out to make a transaction immediately. If I had problems with swap services or Spark knowing too much I'd roll funds out to other wallets. This is including both the LN or XMR side. For a long time I off-ramped zaps into other LN wallets or swapped them already.

It's a private 3rd party in a world built on p2p. Re btc privacy on cake: silent payments.