The Prefitter is still supported. It was migrated from Content Paradise, maybe that's why.

You don't need MD for it, just Poser. MD was used to create the Prefitter. There is a version with the MD files, but you only need that if you have MD and want to create more fitting morphs for different figures. Most people will be happy with the base version.

I've described the workflow above, no MD in it. Just Poser. Load, conform to Prefitter, copy relevant morphs, un-conform, load target figure, dial in the morph, fix remaining Problems with the Morph Brush, make conforming with Fitting Room. No MD in this workflow.

Works for hair and most boots as well, according to the description. I've just made clothes up to now.

Official Documentation

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.