Use the recommended file for a perfect fit with the lens.
The perfect fit version has been tested to work with the 15-45mm and the 22mm ef-m lens from canon.
The wider fit version has 7mm extra diameter if needed (see picture), but I suggest using the other one.
The author remixed this model.
Started from the filled-in gridfinity boxes collection by @jdegs.
Added a hole that fits most ef-m lens, including the one included with the M100 camera