In my experience, I've never been able to migrate any of my presets or custom render templates from one version of Vegas to the next. A support request to Sony was answered with a non-answer that did nothing to help. If anyone else has figured this out, I too would really like to know how to do it!
While it is unlikely the render templates are the same in VMS Platinum HD, (I don't know), once you upgrade to Vegas Pro 12, these threads discuss how you could save and replace your custom render templates for Vegas Pro.
All presets and customizing that I do with VegasPro is always documented (usually with screen cap) to keep records of their values. By doing so I have made my library trans-portable to new versions and different installations. Just docu.and live with it as the best you can achieve.