These inconsistencies are an issue, I agree.
My suggested solution was to use session relevance to get the list of patches that have windows 7 computers relevant to them. This might not be ideal, but it is useful. You need to run the session relevance in the session relevance tester, or the presentation debugger, or in webreports.
names of fixlets whose(exists applicable computers whose(operating system of it starts with "Win7") of it) of bes sites whose(name of it = "Enterprise Security")
The real question is, what are you trying to achieve? Are you trying to make a baseline of all relevant patches for all Windows 7 computers? If so, then I have a solution I am working on to automate this process:
All you need to do is define a session relevance query that returns the set of patches you want to be included in the baseline. Once you have that, the creation of the baseline can be automated by using this same query every time you wish to create a new patch baseline.