I think that the PDK should have a wrapper for the tools that would be aware
of different versions. It should be configurable to define where each PDK
version is installed.  That way we could start the PDK toolset set a default
version to use and select a different version if desired.  I noticed that
PDK stuck itself as the first item in my path. Personally, I dislike
application installations that always seem to increase the size of my path
and at the front no less.