Yep I generally wait for them to be red in my other teams, since two magically cheers them to 100%, but I do think it adds more odds on getting cards/giving away free kicks and on BvB I want every possible edge (one stinking goal at the moment the difference between me and 1st) so I keep them all happy. Since the matches are all during normal waking hours I tend to miss them by being asleep, and so have 0 blue boosters and have to buy them or watch videos when they are available.