I definitely understand your desire to prioritize the neurological angle, but I’ve had some discussions with coworkers and classmates with more of a neuroscience focus over the years about this exact possibility and the answers to “what’s the next step if ME/CFS turns out to be in the brain?” have left me pretty disappointed. It’s far off in a way that most other biomedical research isn’t—a fact that I didn’t fully comprehend until I was walked through the limited set of neurological phenomena that could be measured [edit: especially without an animal model] and the even more limited conclusions that could be drawn from any of it. The few examples of successes with migraine and epilepsy are mostly due to the triggering phenomena in both cases being substantially different to the sort of “broken loop” mechanism proposed here.
If it does turn out to be a broken neurological feedback loop, we’d more or less end up in a “throw psychiatric medications at a wall and see what sticks” scenario.