if you buy the channel and deploy liquidity via LN, u don't use ur own UTXO's, so the UTXO's produced from future on-chain operations are not linked to u. however, the behavior of those future UTXO's is still linked to splicing in & out of a specific Phoenix channel. sometimes it matters, sometimes it doesn't.

i found Phoenix very useful for large swaps thru Boltz and the success rate is very high. the downside is the high swapping fee and high LN fees through ACINQ, so i am starting to think how to minimize those fees.