Surely trial lesson content depends on the HoT at the FTO you're working for?
For example: if I did what Mister Geezer does and was caught skipping the pre flight brief, or even skipping use of the white board to explain the effects of controls, I'd be in for a right ole rocket off our HoT but I totally understand where he's coming from.
However, the opposite may be true at other FTO's which of course is perfectly okay if they're teaching the 'student' something once airbourne and not just up for a jolly....
VFE.