Live microbial media/soil supplements, whether manufactured or home made 'teas,' are usable throughout the grow, from pre-sprouting to harvest. But different specific species and strains do different things for the plant, such as break down wastes, chelate or otherwise increase nutrients' bioavailability, secrete growth promoters, bind to and interact with other microbes and roots, including fixing nitrogen, etc. Generally there are no downsides to dosing the plant with concentrated live microbes formulated for this use. I'm biased to trust manufactured products over potentially pathogen-contaminated home brewed teas, but tea users don't seem to have problems.
ReCharge contains a wide variety of microbes covering a very broad spectrum of activity, covers most every type of activity as I recall. I have used it in feed water from sprouting through harvest.
I currently mostly use the new tablet form of Advanced Nutrients Voodoo Juice Plus (combines the company's 3 microbial supplements). See
https://www.advancednutrients.com/products/voodoo-juice-plus/. The 10 x 1 gram tablets each make 100 gallons (with the company claiming this 10 g package makes 1,000 gallons). I powder or break off just small amounts, using ≤100 mg/gallon (lasts a long time; and I presume dried microbes are more viable longer than those in fluid, which is the format for many of these type products).
