As for being too far along, here is a tip. You can change the type of a component just by going into the attribute editor and changing the
.comp_type attribute on the guide. If the guide nodes and settings match, you don’t need to re-rig the guide. You just tell it that it is something different now, and it will build as the new type.
I don’t know about leg_2jnt_ms_01. But I was able to change my legs from leg_2jnt_01 which the default biped template uses, to leg_2jnt_freeTangents_01, which is what I always use. All I had to change in the guide was “Divisions” to 2 and 3, so it had the same number of joints, and then it built fine and my skinning even matched.
Those two components have all the same guide settings, so all your ikref values should stay the same. Any post scripts might have to change, since some of the controls it builds will be slightly different.
(If you already have animation done, this might not be a good idea, without testing first.)