One more piece of advice that came to mind. Maybe you can negotiate that part of your current responsibilities be offloaded to a more junior engineer with the right balance of knowledge and attitude. This would serve the dual purpose of releasing some of your time for more "research oriented" activities while simultaneously providing you with the intellectual challenge of having someone to mentor for the next 3-4 months. Hopefully after that time you will have a better idea of what you want to do next in your career.
This all of course depends on you having a boss that actually listens and is interested in having the company's personnel grown into the professionals they are meant to be, vs extracting the maximum amount of labor each quarter.