When PL is updated, I assume the FP components are updated based on the FP version that is licensed. For example, I currently have PL8 and FP7. If I upgrade to PL9, but not FP8, the subsequent PL9 updates will only pull in any updates to the older FP7?
Subsequent PL9 minor updates will probably contain also all updates to FP7, FP8, VP4, VP5, but the features presented to you will depend on the licensed version. When new PL update comes, you may check FP and VP release notes for possible new features there.
For example, if you decide to buy FP8, you don’t have to re-download PhotoLab – all you have to do is just enter the new license (and perhaps restart PL).