my efforts at square chisel..

[Crofter]

No I am saying that the sideplate angle is much MORE important. With the bevel file a few degrees rotation makes a big difference in side cutter hook. By comparison a simple round files rotation makes no difference in hook. Only its vertical position controls hook. With a goofy you can rotate the file somewhat to control top plate bevel while the rounded edge against the side cutter makes little difference to its configuration. That is because a goofy is basically a flat file with toothed rounded edges.
A round file or grinder gives about a 55deg. side cutter bevel. With the goofy you can get much smaller angle. It still is important to keep the intersection between edge and flat exactly at the corner of the tooth though, or you will indeed have some goofy looking cutters.