People can and do practice disengagement in many situations besides abuseful ones.

It's an avoidance strategy, it can be practiced whenever someone wants to avoid a situation they are not immediately able to change.

Like a child sitting in a classroom listening to the teacher explain something for the fifth time that he mastered long ago.

Daydreaming in the car is not the same thing as disengaging during school to avoid boredom.

And only the parent really knows if its happening and if so to what extent.

Personally, I don't think it's a good measure to ask the child if harm is being done. Unless they are teenagers it may be hard to get an accurate report. I think the responsibility is on us parents to make these decisions.

Obviously gratified had made the decision that it isn't a problem, so that's the final word.

Again, I'm offering a different viewpoint based on what I know personally. Indeed, my sister thinks it's a great way for a gifted kid to survive a non-optimum school fit. I've heard the same from others. I just don't buy into it. I think it's a cop-out when the child is in the position to have to adopt this behavior for long periods of time during the school day because their educational needs are not being met.

Key phrase being long periods throughout the day. I think it's harmful and conditions the child to be ineffective and non-productive. Do any of us know people we care about who seem to be "spinning their wheels" a lot of the time?
That's the issue that concerns me.

So, maybe it's less that I'm wondering about gratified's son; and more that the comments hit a nerve with me about something that is a big pet peeve.