It has been like that for many years: With every new release you get a new version fo VEGAS Pro installed next to the previous versions. Same applies for plugins. So you basically ended up with copying plugins back and forth. It has it's advantages and disadvantages.
I created a set of installers for each major versions. But they just differ in the internal upgrade code and the version detection. They still deploy the same version of the connector. Maybe that'll help a bit.