i have a new set of crests with mud xs fitted, running tubeless- no real issues for me (and this was my first go at tubless and I was expected a faff)
my tyres were already well used though – so not sure if that made a difference. Just using yellow tape and JRA sealant stuff
I fitted the tyres with a tube first for a few days
then took the tubes out, fitted the valves, rubbed neat washing up liquid round the beads, poured in some sealant and pumped like crazy with a track pump. One of them was loosing air for a while round the valve – but I rotated the wheel so the valve was at 12 oclock and the sealant seemed to find its way to where it needed to be.
Pinches advice for getting the tyres on in the first place sounds right