I can see a couple situations in which it might be useful, but I do think there's a good possibility for it to be misused, and I'm not sure the situations I'm thinking of would absolutely need a research tag.
If someone has a question about setting up an experiment, measuring some part of a system, or something else that is a part of the research, it seems to me that research would be a meta tag in that case. We don't care if it's for research or testing or anything else, we just want to know about the system itself and what you need to measure.
However, if the question is actually about research procedure on an engineering research project, I could potentially see that being in scope. Somewhere like Academia.SE would probably be well-suited to handle a research question, but that doesn't necessarily mean that they would be able to fully consider and analyze the engineering aspects of it. I don't know that the tag will be used in this manner, but I think it could.
So my feeling is that we should let the tag live, but watch its use and make sure it is used judiciously. It may turn out that the appropriate questions turn up and it becomes more meta than useful, but I don't know that that determination can be made yet.