I swear by it personally, but use it sparingly. Actually have different types - sulfured molasses, unsulfured and dried stuff from build a soil. I only ever use the sulfured molasses and dried stuff, and I use not even a 1/4 tsp dry mollases per gallon and not all the time because of my environment, it can lead to problems for me. I use the dry stuff for FPJ too, the liquid stuff has more osmotic pressure which effects the resultant FPJ extract. Nothing wrong with the liquid unsulfured stuff though, I just think you might need more of it? or i should say... the normal dose. the dry stuff I have to use less of.
The dry stuff i use in tea's (depending on the tea, usually 1/2tsp-1tsp/gal, it gets eaten up by time the brew hits sweet spot). and later in flower at 1/8tsp - 1/4 tsp with waterings to directly water in without a living tea. Sugardaddy from Technaflora is awesome stuff, used it allot outside of living soil, but the Magnesium can cause imbalances in living soil if used often - that's why i have the sulfured molasses - to replace feeding sugardaddy. But it can affect the microbe life - so every third time I apply dry mollases with bacteria, I replace it with the sulfured stuff instead, and skip microbes. but will follow up next feed with a bacterial heavy tea I innoculated with something like King Crab, worm castings, olly mountain fish comp...anything to replenish. Much like with some terpene enhancers that use botanicals that can hurt the population (terpify, maybe terpinator?, etc), sulfur gives me a noticeable terpene boost and the plants like it.
I believe persephones palate has similar effects to feeding microbes with mollases, so i use that interchangeably with the sulfured mollases too. It contains sulfates from the calcium lignosulfate, and gives a good terp boost, it's a great replacement to mollases if you need extra calcium boost. But in terms of cost, a bag of dry mollases...seems this one will last a lifetime, i'm certain

. much cheaper, can infuse it with calcium chelate or big 6 if I need to tweak it. but mollases already has some selenium, mag, copper, iron, and calcium as it is.
I just know when I use mollases heavy or more than 1/4 tsp every feeding I run into issues, and it can lead to pathogens where I am even. I've had friends tell me they cut down on dosage in the winter months/indoors or only ever use it in tea's. 1 tsp/gal seems to be the standard though, outdoors 1tsp-1tbsp/gal easy no problem!
Even with salts outdoors, if you did a mollases feed and innoculated with some bacteria or fish emulsion, it is beneficial in my experience even in 20 gallon miracle grow pots. Water that in really good to run off almost like a flush- if you think it will be able to dry out enough and not stagnate at this point in season. The bacteria that die will still be cycled in there by something, just don't feed/topdress anymore salts through flowering. Worms though like Willie said wont stand for the salts, they will roll themselves out and into the grass to better pastures, they are too big in size to stand a chance, something salty will be in contact with some part of their body. the bacteria are so abundant and tiny though, you can have little apartments of them extablished, especially where more plant exudates exist near the roots. Plants will still make exudates even to deal with salt stress.
Just take it easy on the sugars, or you risk pathogens is all, especially with lots of salts/nutrients in there if it stays too damp. worms are nice pathogen digesters but they wont eat anything salty. If you aren't chasing bacteria for terpenes, the brix from mollases will still be useful and you need not worry about any inoculations..but if you're trying to shift your soil over to housing some pockets of bacteria maybe innoculate/flush.
The ideal dose of liquid unsulfured molasses, from my personal experience/climate/living soil type -to feed microbes and keep them happy - 1/4 tsp per gal, a little goes a long way. and even less of the dry stuff. But later in flower I jump up. I just wouldn't constantly be giving 1tsp/gal - that's just me though, not the gold standard for everyone. but you are doing salts, and if you leave your pots out for the winter to recycle next season, and aren't too concerned with feeding bacteria - i'd just give the typical 1tsp-1tbsp per gallon for bud development and terps. Long winded sorry, I love my mollases. It's in the toolbelt!