Autofit will work with any TriAx figure that has a purpose built Clone morph, my TriAx Aiko3 has 3 clones (h3,V3 & M3) and can autofit any of their conformers, problem is that I have to use my not so good WM Aiko3 as the projection template, so the WM in the outfits isn’t so good.
In the case of A3 it was easy to make the clones as they all share the same mesh, so you can import their OBJ with morph loader, you do need the CMS running as you then need to change the modifier type to Clone before autofit will see it. Other figures however are a different story, the clone morph has to match almost exactly the size, shape & pose of the figure your making the clone of, so unless you have the toy’s and expertise to use them, it’s a case of pushing and pulling vertices like I do.
As far as converting a figure to TriAx goes, you haven’t changed anything as far as the rig goes, as DS has never use parametric rigging, it converts it into a very basic WM that mimics it, so when you convert to TriAx you end up using that basic WM, so it still bends just as poorly as before (in some strange cases worse). So you might have to re-jig the rig, and alter the face groups on top of painting weights (I’ve got a touch like an elephant so I’m not enjoying painting weights), just to get it to bend better.
One big tip about converting to TriAx, make sure you have every morph INJected before you convert, because once you save the figure as DSF asset files INJections no longer work, as technically DSON doesn’t have an “channels” for you to INJect into.