Nothing really direct to the plant. Supposedly. Although molasses will have some traces of vitamins n stuff. Mainly it is to feed the microbes in the soil. Some sugars are absorbed in plant I guess but there is life in soil. Molasses keeps it happy n shows in the plant. Check out organic gardening here. Barely any nutes used. Just good live soil microbe teas and carbs sugars. I think the carbs /sugars definately help frost them up more too.
I can vouch for molasses. Plain old molasses makes your buds frostier, i have seen this with my nl clones first hand this run. Without molasses “meh, not bad i guess” with molasses “wow, isn’t it a little early for snow”.
Cheap too. Sulphured and unsulphured is open to discussion, i read people feeding bacteria using sulphured molasses and their colonies havent suffered (guess the sulphur is not in a very high concentration) but lets be safe and use the unsulphured ones :)