I have the s10+ and it's actually useful, as you can remap the double click on that button to open any app you like. But yeah single click, never happened intentionally.
EDIT: F yeah, I just checked the settings and you can decide if you want bixby activation on single or double-click. Now I've set bixby to double click and on single-click it opens my password manager. If you don't select anything, it will do nothing on a single click.
The setting is under "Advanced Features" -> "Bixby Key" for me.
Same I just went with Tridactyl without a particular reason. Though their native messaging part, where you can execute stuff like your editor with a keybinding is a nice addon that others don't have.
Note, that you can only get root on the images that don't include google play store.
It's really not that hard, after you've done it once. The first time will include some head scratching and learning about some android gotchas. But after that it will be easy.
ARE YOU SURE YOUR DISPLAY AND THE VOICE IN YOUR HEAD IS NOT LOUDER WHEN READING THIS?