As I was not able to find any relevant information about what exactly the grey-ed out checkbox for video support in Free and Core license/plan means on neither Pioneer DJ site nor google, I had to find it the hard way.
I had to download RekordBox, create a Pioneer DJ account, figure out that I have to enable video features in preferences first, just to find out this:
Video playback is obstructed by a nasty big black banner in the middle of the screen saying "you cannot use this function with your current plan". That means video function is absolutely unusable even for home use.
In order to use video, you need to get RekordBox subscription.
As I was unable to find this information anywhere, I use the opportunity of having a Pioneer DJ account now to let others know.
I thought purchasing a Pioneer DJ controller with included RekorBox would be a better value alternative to other controllers in combination with VirtualDJ, but unfortunately it is not if I need video playback.