Doh! Didn't need to do the above...

I figured out my issue. I just wasn't selecting the bloody pants in DS4.5 when I was running the Save as->Support Asset->Figure/Prop Asset method. He he.

The issue was just my unfamiliarity with even the rudiments of DS4.5.

Got it working now. The correct .dsf is now being created under the data folder with my Poser Genesis runtime, wherein I'm saving the .duf.

I notice one thing straight away... I need to dial up the Genesis figure to the shape I want, e.g. Heavy, Child, etc, before I drag-and-drop confirm the pants. Not a bug, as much as just how it needs to be done, I guess.

Although, on mac at least, there's a weird glitch with the UI Dialog that pops up during the "Projection" phase of the DSON Importer assisted conform operation. It just flickers, stuck on the 00:00:00 time remaining, until it is done. I think the UI Dialog is being invoked and destroyed many times, on each iteration of the underlying program loop.

Otherwise it looks to be working.