It can be if one wants to. For example river has its own protocol for letting clients arbitrarily position windows. There's a builtin one that does tiling, and

It can be if one wants to. For example river has its own protocol for letting clients arbitrarily position windows. There's a builtin one that does tiling, and then a bunch of user-created ones at https://codeberg.org/river/wiki/src/branch/master/pages/Community-Layouts.md https://codeberg.org/river/wiki/src/branch/master/pages/Comm... But yes, it requires such extensibility support from the compositor, unlike this project that works with any X11 compositor because it just relies on EWMH.