Howdy tjcny
The theory is that sweeteners help improve taste.
Some use--honey and have seen YouTub video with big outdoor grow using brown sugar at end of grow. This idea is controversial--more anecdotal or opinion based.
However, molasses and in particular--Black Strap Unrefined Molasses, has high K which some give towards end of harvest to feed what is called the micro herd (good bacteria).
I have been growing in coco for a few years. And have not used any molasses. Though, I have used the GO--CaMG+ which is composed of some fermented sweetener (think it is molasses).
Yes--I think it will cause some problems in your automatic feeder. You can just hand deliver. I am going to try a self watering system too. Decided to just use it for watering and will add magnesium (epsom) salt to get the EC/PPM of the RO water up to around 150 PPM. My little inexpensive unit states boldly--do not use any fertilizers etc.
Others who use molasses consistently will drop by with their thoughts.
Typically, molasses is used by soil growers. Though some using soiless or even hydro add it to the mix.
Good luck.
Cheers