the swapping out process is free on Phoenix, you just pay on chain fees. But Phoenix beeing non custodial you'll have to pay a 1% fees (or a minimum of 3000 sats) to open a channel between your mobile node and ACINQ node (all of this is automated of course) So you better open a big enough channel once and for all (send all your funds a once to Phoenix) rather than many smalls one, but otherwise Phoenix is the best solution IMO Non custodial and free swapping out