In the time since, I brought another iMac and had 2 work MBPs.
In that time, MacOS got worse. It now wants to make windows full screen. Mission control is awkward if you use an ordinary mouse.
My workflow has changed. I'm more likely to have 2 windows of every app- 2 vscode windows, 2 terminal windows and 2 browser windows. As stated many times over, MacOS handles switching between those configuration of windows badly (and I gave it plenty of time to become intuitive).
I now use the Gnome desktop. I have windows that snap. I have alt tab that cycles through windows (it needs configuring). And it has an Expose like effect (gnome overview).
I feel like I have the best of all worlds. Great window management. Great hardware support (none of the MBPs supported daisy chaining my displays). The Linux command line. The same apps I'd be using on any other OS.
macOS does a lot of things very well, just not that.
The fact that cmd-tabbing to a app will place all of its windows on top means that I might be forced to move a window with the mouse to see what's underneath it which I find infuriating. The fact that two windows belong to the same app is an arbitrary distinction to me. I group things by mental "projects", and I prefer to maintain my window z-order based on that.
I never liked using virtual desktops and I just downloaded altTab which I've read about in threads here, but it seems to flicker weirdly and it has already crached on me once within a 1/2 hour timespan so I don't foresee myself keeping it.