I created a mounting plate for the MAD system on an Ender 3, I also modified the base MAD mount and the dual 5015 bracket to avoid clearance issues with the X axis gantry. The mounting plate is also setup to use the metal bracket that comes with the BL Touch.
The way I have my printer configured, my effective build plate space is 235x214, You could likely get more space but I haven't 100% completed that part yet. I have uploaded my printer.cfg for reference.
The author remixed this model.