Hello,
Thank you for this great software!
I have a Microsoft Surface Laptop 7 with Qualcomm Snapdragon X arm64 processor. Betterbird for Windows (x64) works okay using Windows' Prism emulation layer, but it stutters a bit.
(sidenote -- disabling accessibility features seems to have helped with the stuttering)
It looks like it's possible to compile Thunderbird to run natively on Windows (arm64), but requires some tweaks. There's a user on the Mozilla community who successfully compiled Thunderbird on Windows (arm64) (see his post here). It'd be great if Betterbird can provide a Windows on ARM build.