To restore a minimized window, cmd-tab to that app, then control-down arrow to show all the windows of the app, then use the arrow keys to select that window (minimized windows are smaller at the bottom), then return to open it.
Oh, wait. I just tried and it turns out you can simply use the up down arrow keys once you've tabbed to the app. Neither control or option keys are required just keep holding command and then use the arrow keys. Who knew?!
Not perfect but better than nothing (which is what I had before).
Hmm, doesn't seem to do anything for me. I tried with both maximized and desktop windows (multiples of the same app, Chrome and VSCode) but pressing down just results in the app selector bar disappearing.