I do not do these often because they are not often indicated.
In this case, removing part of the MO composite resulted in a pulp exposure and easy access to the mesial root.
Got lucky with the access into the distal canal.
Finished by packing amalgam into the distal entry until I could see amalgam coming through under the pulp chamber roof into the mesial entry, then placed more in the mesial.
Nice, Kehn! Just from a structural engineering perspective, retention of the dentin truss—I don’t see how it cannot but help mitigate some of the cusp flexure that endodontic cases are subjected to when the truss is removed—as it is in more conventional endodontic accesses.