Custom property builder has no APIs. What if you just replace those prtprp, asmprp files with new ones, aren't they picked up automatically?
Thanks for your response. I think your suggestion would work in most cases. Unfortunately those templates built with different names all over our network. A bit of a wild west thing that I try to solve currently. If I choose all parts for example and try to update the template Property builder do not allow it. It only allows to change templates which are with the same name and path.
This is reported as SPR# 526125. I am trying to figure out a quick and dirty workaround for this issue and make our templates correctly. Or Did you have something else in your mind that I did not get? Anyway again thanks for a quick response.