Not for container growing. They are not necessary with the ratio you get with dyna gro. I did see homebrewer suggest that floralicious plus during all of flower will slightly improve taste. you use it at 1ml/gallon all through flower.
Check with any old timers and you will find that bloom boosters are reserved for those who like using 20 bottles of shit instead of 1 complete system. Look around a little and see how much people like dyna gro or jacks. Much cheaper and much easier without any sacrifice in quality.