What type of client problems have you run into? I’ve only recently started to use it, so I am looking to avoid any pitfalls if I can.

It’s definitely not perfect, but I’ve been running Gnome Wayland on my Nvidia card for close to 6 months, and haven’t had too many problems.

I don’t know about this specific program, but pretty much every other time I’ve seen something like this it’s been treated as another language and is a way for developers to test that that feature actually works.

I haven’t verified that everything is totally there, but Proton has all their stuff here: https://github.com/ProtonMail