Considering leaving after three months
I can't figure out what the formal relationship between you and this company is. Do you still have some contract with them, as well as with the University?
It seems to me that asking your advisor about the situation regarding say IPR or liability insurance may give you a lever you can use to get out of doing the company's work. E.g. &quot;... requested me to finish the limited demo ...&quot; so if that was done as part of a full-time PhD then is it you or the University that owns the code, and not the company at all?