If I submit one of my unpublished work on researchgate which I have not completed due to lack of time and intended to finish later, someone may steal the idea and publish before I can publish.
I am in the same situation but I believe publishing early work is actually an advantage!
a) you can get feedback (or offer for co-op) and improve your article
b) you will have a recorded publication time, so it _saves_ your idea from someone else publishing it, you'll have prior-art. So if they publish your idea as a novel and theirs, you or a responsible journal should attack them for not citing your prior art.