o.k. thanks for the info.  there are some other ways of merging, thanks to poser developers/philc.  for new runtimes enclosed in an identifying folder that contains the runtime and readme, I dump those in the downloads folder.  like daz method, but without segregating out all the subfolders or even the dreaded overwriting of existing folder content, which kaveman wisely warned us about, but which I never actually saw in action.