>So it's never wrong to try a pacing approach to see if it helps.

How many people who've had chronic fatigue or post-exertion malaise for a few years do you think haven't tried pacing?

I'm sure some have not tried it, but for most, it is a natural thing to try even without a health-care provider or online source suggesting it.

I would say most of the 100s of patients I have seen w cfs or fibro haven’t given pacing a good try - either they do t have the common sense you mention, or they do, but are unable to make the changes required to actually pace. Ie making boundaries with family, leaving an abusive partner, taking time off a cherished job etc. And then, it is very rare for a person to, once they have removed these more external sources of stress, start to work on pacing their internally generated stress (ie “free floating anxiety” etc) through dedicated mindfulness and appropriate psychotherapy.

OK. Also, I can see how a patient might neglect to consider the hypothesis that he must pace mental work as well as physical work.

Exactly - mental, physical, and emotional work. IMO real pacing is extremely difficult, requiring a real transformation in life approach over the course of 3-5 years. And without certainty that making the sacrifices will pay off, most people take only half-measures, get poor results, and conclude it doesn’t work.