I never stated that trading volume adds value to privacy, I stated that LN does not have channel capacity for large transactions.

Regarding few transactions per block, which will depend on the hour and day as with BTC, the very nature of XMR takes care of that, no one will ever be able to link on chain the entrance address of BTC with the exit one to BTC after passing through XMR, obviously, the user should use logic and split the output from XMR into BTC into at least three transactions of different values. A non savvy person may put 11.11 BTC in an atomic swap and in under 40 minutes exit XMR to BTC with 11.11, technically it will be impossible to link them, but logically, there is room for tagging the transaction as possible match...