I don’t know for sure, but I’d think glamping is against the ethos of settlers. Settlers are the for those who’d normally go on a week long camping holiday and settlers gives them a fairly cheap 3 days of camping with entertainment thrown in.
I’ve not done settlers but have camped at the Glanusk campsite (At the back of Orange Parking) a couple of times and can totally see the attraction of settlers it’s a lovely location with or without the festival crowds.