Wow - I can relate to the sentiment of 'being toyed with for amusement'! LOL My DS7 also dawdles when changing into PJs (or into day clothes) - even when he knows he's losing reading time, or something else. Sometimes he just wants me beside him when he changes - no idea why. DD at the same age was so much more independent (with clothes anyway).

Last school year DS7 was in the after-care program. The program was in the gym and the caregivers would have the kids keep their stuff in the changerooms. At pickup time, DS had to go into the changeroom to get his stuff so we could go. So, after convincing him to stop playing with friends because we needed to go, to would disappear into the changeroom - and we'd wait, and wait, and wait. Eventually one of the staff would go and see where he was - he'd be lying on a bench or the floor - just doing nothing. Did he need quiet time? Was he thinking? Was he overwhelmed with the task? I have no idea.

Eventually one of the staff set up a race between him and his best friend - he timed them. Lo and behold - he was coming out of the changeroom in seconds!
It's strange because he is usually not competitive, but sometimes a little competition seems to motivate. (At home though, any attempt to do something similar usually backfires.)

DS is also the last one to get ready in class - he does have a DCD diagnosis, so some of the slowness seems to be poor motor planning skills. But it's puzzling because when he wants to he can be quick.