I think the wadu may become makrooh if you fall asleep (not dozing off) because I’ve read instances where Prophet (pbuh) used to sleep after Isha and then get up in the morning and pray Fajar. I know we are nothing like him but we do follow him, right?
I agree and I didn’t say there was any hadeeth, it’s just that there are certain manners that we should follow. i.e. Don’t lean with the wall, sit like most of other people are sitting, unless you have any exceptions.