I missed that as well. I'd say it isn't explicitly wtriten anywhere, and since it says several times that you can still withdraw them but you won't be ablre to use them for zapping, it's easy to asume that you won't be use them for anything other than withdrawals, I think. And that's probably what happened to me until I read this. :-)

My question now is whether it'l be possible to deposit sats to keep a positive balance to use for those payments or once the balance gets to 0 you'll only be able to pay for those via external wallet or CH?