Edit: just tried this and it didn’t work. Proton bridge only listens on 127.0.0.1 and doesn’t accept incoming connections due to security concerns.
If I were in your position, which I am and will probably end up doing this, is vpn into your home network and just connect to the local IP of your bridge server.
WG tunnel on F droid allows for you to auto connect to your wireguard server when you leave your home net, and auto disconnects when you get back on your home net.
Personally, I’m unsure if proton bridge listens for external request or if it only accepts requests from localhost? If that’s the case it may be an issue.
I have been using Gadgetbridge for several years. The developers are very active, with the nightly branch being released daily. I’ve collaborated with some of them to debug issues and add support for new devices.
I’ve used it with multiple watches and a scale. While it doesn’t provide insights or interpretations of your data like proprietary apps do, it offers complete control over your data. I’ve been planning to set up a SQLite to InfluxDB/Grafana translation layer to obtain more detailed statistics.