Does this tyre have tread to go on the front? Is it safe to put it on the front ?

No… you never move worn tires to the front. It’s the other way around. If you’re trying to be frugal and get the most you possibly can out of a tire, in the summer you can move a partially worn tire from the front to the rear.

Moving a worn tire from the rear to front, especially at this time of year, it’s only good for your orthodontist.

That’s also a massively wide tire for the rear… why 2.8? You also don’t generally want a wider tire on the rear than the front as it messes up the grip balance. Usually you want a wider, grippy tire up front as you want your grip balance to either be equal or more grippy up front. It’s generally preferred that your rear end begins to wash/lose grip before the front does… again for orthodontist reasons.

MTB tires are fluid. One man’s front is another man’s rear.

The only ultimate tenet is that you should always have more grip at the front. Usually that means a faster rolling tread pattern in the back, but you can also match treads but get get a softer compound in the front.

I like the high roller as a rear tire on a mostly-gravity bike. For trails I don’t think it pedals good enough.

And I’ve never liked high roller or any of the DHx tires on the front. Maybe it’s just me but I’m not a fan of designs with sparse nubs as a front tire. I want that intermediary zone.