I get what you are asking for but I don’t think it is even necessary to have a list of users on the client in the first place using the MPA approach. I would guess the list of users is just available to the server, which pre-renders HTML out of it and provides it to the client.

If you are interested try Localsend, its even less effort than sharing via a messenger and its peer to peer. You can enable auto downloads for trusted peers then it will be sent directly to a folder of your choice once you send from your phone.

In Pisse sitzen

Fairphones have them too.

I don’t know what a Fairphone costs where you live but where I live the Fairphone 5 starts at 550€ and the model with more storage and memory is 629€. That is no where even in the near of three times the price.

There are phones that give you this choice. The Fairphones for example. The back cover is easily removable and you can pop out the battery like in the ol’ days. It has an IP55 as far as I know.