In Blink you actually have 2 wallets: one for sats and one for stablesats (another idiocy). But the top balance you cannot change it into sats/BTC. Also you cannot change the default display in sats for any generated invoice. You have to do it manually each time you want to create an invoice in sats. And if you are not paying attention, forget that is in fiat, you could end up in making an invoice with a huge amount of sats. That means the payer also could be fooled and pay it (not going to happen usually) or giving errors, frustrations etc.
A simple way is to let the user to choose between which currency to be displayed. But yeah we have too many squareheads fiat maxis using Blink that do not underdtand the need for that feature.
SOME PEOPLE REALLY LIVE IN A BITCOIN STANDARD EVEN THAT ARE NOT IN EL SALVADOR.