You must be referring to entering a VP license number into PL some time ago because I never did that with PL4 or PL5. I was never asked.
I suppose it might be that since VP is listed as a valid license in my account, then when I activate PL using that same account it understands that VP is licensed and then turns on the VP functionality in PL. If I were doing the coding for PL and needed to validate that VP was a licensed product on the system, that is how I would probably do it. Much cleaner and invisible to the user.
However the trial does not require a valid online account for PL and thus the trial would not know about whether or not VP was a valid licensed product for a user. I guess I will uninstall the trial, reboot and reinstall and see what happens since VP is no longer accessible on my system.
The way the license and “plugin” functionality works in PL is the main reason I suggested that VP be a good place to put stitching and stacking. I also think it fits in nicely with perspective because when you stich a panorama you do need to do small perspective corrections to get the images lined up.
Another reason is if someone does not want this functionality then they don’t purchase VP and then don’t clutter up the PL interface.
As @Joanna has pointed out, the only reason you have access to any of the Viewpoint tools is because you had previously purchased a license. Those who have not purchased a license will not see the perspective tools, the Volume Deformation tools, and the Miniature Effect tools. The same holds true for FilmPack 5 Elite and FilmPack 6 Elite. The features for Viewpoint and FilmPack are not add ins. They are a both already present in PhotoLab. All the license does is make them visible so you can access them.
No problem. It can be a bit confusing. That is why you can still see the functionally in PhotoLab even after the Standalone versions of Viewpoint and FilmPack are uninstalled. If you also delete the licenses for the imbedded versions of Viewpoint and FilmPack the features will no longer be visible.