witch tubeless tyre would you have ?

what size, what kind of riding, ust/tubeless/tubed?

tubeless tyre, xc riding and doing the dufi enduro this year 26" 2.1/2.2

2.1 Rocket Rons here!

Nobby Nics UST here for the last eight months with no problems at all. They seem to be just right in all conditions.

No choice

NN front and RR rear

Or having used Mud X's tubeless over winter, maybe a Bontrager TLR?

NN front and rear in Winter RR rear in Summer.

Nice Cham

My experience of the Dyfi and a few other of the longer events suggest that you'll get the biggest benefit from something that will roll nicely on fire road and gravel. However, some of the singletrack descents will still need a half decent tyre if you want to push it.

Mostly I do ok on something like small block 8's, but if you hit some long stretches of sticky stuff, they fill a little too quick.

Perhaps a decent light all-rounder at the front and something closer to a semi slick at the rear would give a bit better grip and confidence for muddy descending, yet give a similar rolling resistance by having a pretty low profile rear.

based on how Scienceofficer describes the route, I'd go for 2.25 Nic up front (Nics come up a bit small, the 2.25 is a nice size) and something like a Maxxis Larson or Schwalbe Rocket ron out back. The front wheel will hook up nicely, the back may slide a bit ont he descents but adds to the fun!

for regular conditions (if you need traction climbing technical trails) I'd swap out a High Roller on the back and keep the nick on the front.