I haven’t looked into it particularly deep but it’s not like there’s a ton of stuff a WM can possibly do unless the code base is littered with raw X11 calls everywhere.
Most of the window placement and tiling logic shouldn’t be tied directly to X11 and only a small part of it should really be interacting with X11 to place and size windows. So one should target that intermediate spot that makes all the X11 calls.
And if the code is too shit to port, it probably deserves to die.