On @FlagrantError’s pointer, I tried out Rectangle as an alternative to Amethyst. It’s not (currently) a true tiling window manager, but holy smokes it’s fantastic! I’m trying the Rectangle Pro features with the free ten-day trial and it’s a 100% certain purchase for me. It’s absolutely packed with smart mechanics for managing windows with keyboard shortcuts and/or a modifier + mouse combination. Repeated activations of a shortcut can cycle through multiple configurations. And there’s a brilliant feature to activate the “mouse throw” of a window using multitouch activation on a trackpad. I’m totally hooked on it.