ok thanks.
I found this. like described over there, I removed the packages from the directory. now they are not shown in the package managers’ list of installed packages anymore. cleaner now 
giving the package manager the ability to only show packages that are relevant for the rhino version it is running on would be a good idea. again: would help to avoide confusion.
looks like v7 isn’t for me at its current state. was curious if my AMD GPUs are finally better supported by cycles but the performance is still bad, so no improvement here jet. it really is a shame that AMD GPUs don’t perform nearly as good as they should.
I wonder if it is the same situation on Rhino for Mac. does rhino-cycles utilize AMD GPUs better on OSX compared to windows?