I've found that you can have any number of runtimes but the trick to getting Poser to load quickly is to have only the 2 Poser runtimes linked at the time you close the program.  The next time you load Poser it uses the xml file it writes at close to link runtimes and if no external runtimes are linked when you closed Poser, there won't be any to link when you open it again.  It's become a habit of mine to off-load any external runtimes I've been using when I get ready to end a session.

Hugz from Phoenix, USA

Victoria

Remember, sometimes the dragon wins. Correction: MOST times.