FWIW: I don't feel like "bloom boosters" do much. I've been using Pennington Alaska Pure Kelp in late flower. I think that does more than high PK. In veg/transtion it seems to cause stretch. I think it has growth hormones from the kekp. But, in late flower when all the growth is in the buds... I think I see it doing something there.
There's a thread about it here:
https://www.thcfarmer.com/threads/alaska-brand-pure-kelp-during-flower.91334/
Regarding synthetic "bloom boosters" remember the NPK label is a percentage of weight. If it says 0-50-30, that's *strong* compared to an ordinary fertilizer that's 10-10-10. The booster has 80% nutrients. The ordinary fertilizer has 30%. That gives you an idea of how little you should use (and how should cut the ordinary fertilize to accommodate the stronger stuff.).
If you get into this stuff, I have a spreadsheet that lets you mix various products together and see the resulting NPK ratio & strength. You can look at multi-bottle "schedules" to see what arises from their combinations. And then hit those same numbers with whatever you've got. Just from an informational perspective, I think that's valuable because it gets you thinking abut NPK ratio and strength. That's a more concrete way of thinking about it. (If you want it, let me know.).