Why not install into $PREFIX/bin? I think that's the conventional behavior.
I can understand why you might be reluctant to do that because ~/.local/bin
likely isn't in $PATH for your desktop environment, but I suspect that the
proper fix is to symlink from /usr/local/bin instead of putting the
application there. I'd prefer that users didn't need to run the installer
as sudo unless they modify the PREFIX to be a global install.