No, AFAIK, it only avoids increasing symptoms. Gluten causes symptoms for celiacs, and exertion causes or increases symptoms in most PWME. Avoidance of exertion doesn't solve ME.
Identifying the mechanism of PEM would be helpful, but wouldn't necessarily lead to a treatment for the baseline symptoms of ME. I stopped having PEM, but my baseline symptoms were unchanged.
I think identifying the mechanism of PEM might be as difficult (and resource-consuming) as identifying the mechanism of ME, with less return on that investment. Physical exertion causes too many effects to easily identify which one is involved. There are also different responses to types of exertion; I triggered on what seems to be muscle damage, while others trigger on duration of exertion. Then there's cognitive exertion, which seems separate from physical exertion as a trigger. Some of us have found PEM blockers or reducers, from completely different chemicals. Dreadfully complex.
If we came up with a treatment for ME, that would solve the PEM problem too.