I might be wrong, but wasn't there mention in one of the threads here, that by being able to select different runtime folders, you could store them onto CD, DVD, or an additional hard drive and just load them up as you need them. Most computers now have a CD writer with them, I've been backing up sections of my runtime folder onto different disks. If it is possible to select a runtime folder from disks and other removable storge devices, then I could use without havig to have both versions of poser on my computer. It would also save a hell of a lot of hard drive space.

Daz Studio 4.8 and 4.9beta, Blender 2.78, Sketchup, Poser Pro 2014 Game Dev SR5 on Windows 8 Pro x64. Poser Display Units are inches