I have use a DVD for my Runtime folders before. Did not have any problems using it other than it was a little slow.
How I did it was after I made my DVD which had  several runtime folders...Animals-People-Props and so on...
Anyway after I made the DVD  I copied all the Geometries and Textures from the DVD into Poser.
It worked fine and I didn't have a lot of things inside of Poser. However as I said it did run a little slow in that way, but I also have an older slower DVD drive and not a lot of ram on my system.
Hope this helps