If those countries are in the EU, you have the right to use a bank based in another EU country. The traditional incumbents will likely demand an in-country residential address (in direct contradiction of EU law). Which leaves the internet-only neobanks. I believe the only FOSS-compatible option is Wise, which has a modern web offering and does not even require that you install a native app. I understand N26 does, but it may work with Graphene. By contrast Revolut is a privacy-invading walled garden and should be avoided at all costs.

You’re right what the law says, but then you run into the Italian tax authority that will only accept an Italian IBAN to pay taxes.