Bloom boosters aren't needed if you have a balanced formula and proper pH.
Well I grow in coco so a balanced PH is a must and I wouldn’t say I used those as “boosters”. The way I used them I just considered it a way to cut down on the amount of N in mid-late flower. I also did it to give the plants a better regimen that fits their needs during flower, lower N, more P early-mid flower and more K to finish.
I’m actually switching to PBP soil and now have to figure out a way to give them more N during veg and early flower. But I have another few months to figure that out as I’m in the middle of a seed run. And for seed runs I use cheap blue powder nutes from Walmart since I won’t be using the flower and only need them happy enough to make seeds.