An external mouse on a laptop, as mentioned before, is counterproductive. If on the go, a mouse a pain in the rear to use. If stuck in one place, such as at a desk, a desktop machine provides better cooling, and should be used in place of a laptop. I’ve also found first-person controls to be clunky on mice, anyway. A track stick has always worked best for me, though a touchpad works almost as well. Still need mouse buttons though.
Besides, combinations aren’t the biggest problem, as I’ve repeatedly said. Having even a left click without simultaneous right click is necessary just for basic desktop usage, and not all desktops emulate mouse buttons that shouldn’t be missing in the first place. I’m so fed up with GNOME/KDE/Xfce, and I can’t switch to something simpler, that doesn’t force obnoxious features on the user with no way to turn them off, because such simpler desktops don’t emulate missing mouse buttons. Without basic mouse buttons, getting any work done whatsoever requires me to be stuck on a desktop that has driven me bonkers for years. There’s a reason I haven’t used GNOME since near when I first started using Linux. GNOME isn’t for everyone. This shortage of mouse buttons on the Librems *severely constricts* the range of desktops that actually function.