I used to be a fan of tiling window managers, but I found out that I tend to use fairly visually heavy apps on a Mac. By this I mean apps that need quite a bit of screen real estate to show everything that needs to be shown:

The mail program has a folder tree on the left, the list of messages in the center, and the current message on the right. The IDE has all these tool windows that need showing, in addition to the actual editor. Websites also like it if the window size is a bit more.

Back when I was using Emacs and xterm, mainly, it was nice to show Emacs in the left half and then two xterms on the right.

So instead of tiling, I've come to realize that I only need a couple of window positions and sizes: Mail program and IDE are full screen. The browser occupies 70% width and height, in the top right corner, and the terminal is in the bottom left corner, 200 columns by 44 rows or so. (Lazygit works better if the terminal is a bit larger.) The chat program is full height, 60% width, left edge.

In this way, while the IDE is building or running tests, I can summon the web browser and still see at the bottom and on the left what is the progress of build or test. Also, when I use the software through the browser, I can see a couple of lines of log messages, which is enough to tell me whether to switch.

So I'm now happy with hotkeys in Hammerspoon that reposition and resize the current window to one of these presets, and to jump to a specific app with a keypress. I use a modal for this.

I dig the idea of having multi-level modals, somehow this idea never occurred to me.