"boosts" that I use are topdressings around week 3 of flower, which break down during 4-7th weeks. Mainly just go for NPK of "low"-"high"-"medium" in number, like 3-7-4 for example. but it all depends on if you think it needs it. I started using bloom enhancer like that because my soil mix was not producing the yields i knew plants were capable of, they were fading a lot to soon, and you could tell the mix was not complete. Now i'm trying to enhance the soil nutrition more by going with 2/3c of amendment per cu.ft. with certain amendments so I don't have to worry about topdressing. if they show no negative signs, i'm gonna do a mix with 1c per cu.ft. of certain amendments and see how that goes.
you can get into bokashi/fermentation which extracts nutrients in a liquid form and you can feed those to try and give a boost. also AACT with quality EWC will contain chelated and solubilized nutrients that will feed plants, and also boost microbial activity which will results in more decomp, and faster nutrient delivery (speculating here).
also, well timed use of auxins, salicylic acid, and cytokinins will also have an effect on flower production and speed, but you need to apply these product with a specific purpose, and not just as an "additive". I would recommend researching what those particular hormones do and that will give you a better understanding of when to apply them in small doses.