Thank you both. I put him in the back to front onesie again for BT and he did exactly the same as at nap time - basically ended up crying so I had to go in his room a few times.
I think I will stick with nap as is, Haribo. Difficult as he is to read, I just have a feeling that cutting it further could spell ( even more) disaster.
Oh I wish he would just go to sleep without all this messing - it's just so exhausting.