I have found nothing but issues when trying to UV coat after creasing. I do a lot of newsletter covers and brochures on heavy stocks. After the sheet is printed, I coat it and then crease it. I usually do gloss, but have done a good bit of soft and matte. Just make sure on the soft and matte you have your IR lamp turned up real high. If the coating isn't fully cured onto the sheet, you do run a risk messing up the finishing machines.