Not specific to grapheneos, and also battery friendly on LOS is localsend, and on gnu+linux I use instead localsend-go since it offers a CLI (what I use) and a rudimentary TUI which is missing some functionality but good enough (I prefer using it as CLI). But localsend also includes a windows app BTW. On gnu+linux some prefer kdeconnect, but I find it more battery intensive than localsend on the phone, and the extra functionality is not what I expected, like I originally guessed I could write sms from a gnu+linux box, or read past one, and that’s not what sms control means.

Don’t these alternatives work on grapheneos for some reason?