I’m running the carbon version of the Ibis 35mm IW wheel on my Ripmo AF.
I bought them as a total experiment to decide if wider really is better. I absolutely love them and would never go narrower on my big bike, I can get away with super low pressures without dinging rims and have more traction than I know what to do with.
That being said, I don’t think those wheels would be ideal if you drop below 2.4" wide tires. with the maxxis WT designated tires you would probably be good.
It really depends on what your ride dream is, if you want to smash rocks and have all the traction, for sure go 35mm. If I was outfitting my XC race rig, I would go with the 28, but if this is your only bike and will be your trail bike and race bike, I think you would be happy with the 35mm.
I have two coworkers w/ V4 Ripleys w/ the 35mm and they both love them. My boss mounted up some 2.4 Rekons and rode it in the Dakota Five O 50 mile MTB race no problem.
Especially if you are coming off of a 27.5 +, I think you will love the mega volume and inherent grip of a 35mm internal width 29er!