I can confirm that this works for me on i3. The default bindings are alt+click to move and alt+right-click to resize. Those are rebindable of course and I get a

I can confirm that this works for me on i3. The default bindings are alt+click to move and alt+right-click to resize. Those are rebindable of course and I get away with using one of the extra buttons on my mouse (specifically a ring finger click) to enable the modifier.