I used Gnome for a while and I just made my own very simple extension then, which was just a bunch of keybindings to move and resize the focused window. Super for a 2x2 grid or Super + Shift for a 3x2 grid, plus a Numpad key to place the window on the grid.
I guess it would still work with 40 because of how simple it was, but even if not, it would most probably be trivial to update, so you might want to consider this route.
In the past, I used an extension called Put Windows that was perfect for my need, but that stopped working on Gnome 40.