Not to diminish the work put into making this workflow easier to use, but you can completely replicate this workflow (and then some) with out of the box macOS tooling by creating an "Open <xyz.app>" script in Shortcuts, moving them into the Quick Actions folder and then jumping to System Preferences > Keyboard > Shortcuts > Services and then assigning key combinations to launch Shortcuts.app Quick Actions.

For sure you can. I had this workflow with manually added keybindings through many methods over the years: skhd, Hammerspoon, BetterTouchTool etc.

I just found that the functionality is useful enough to warrant an app that can dynamically assign these hotkeys based on the apps I use.

For example I change browsers often to test new additions. And because I have rcmd-B set to focus/launch/hide my current browser app, I can keep my muscle memory even after switching from Safari to Firefox. In rcmd I just press rcmd-ralt-B to reassign that hotkey, in previous workflows this involved editing a specific file, or opening a preferences window and finding the right setting to change.

The experimental window switching/opening using Right Option is also something very useful and really hard to replicate using default macOS tools.