Optitex works fine in DS4. I don't even have the paid plug-in, just the one that comes with Studio. If your model has above average measurements, I normally fit-to, hit control+c to copy the location, then fit to none and hit Control+v to paste back into location and line it up over the character. You can also try scaling it larger than your character's dimensions, so long as the collsion commands intersect or fall through the appropriate places.

EG: My Scarlett version with well above average proportions:

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