I bought my Levo used from a shorter guy that had switched the wheels to 27.5 with 3.0 tires front and rear. Rode it like that for 6 months and had no issue with it. But, I am a notoriously a not picky rider, lol. I recently switched to a 29 up front with a 2.6 dhf and kept the rear at 27.5 with the 3.0. The thing rails! Feel like a I got a little more rake out of the front, reduced Head Angle, and the front end is much more precise. So, Obvs, I came at it from the opposite end as you, but must say I like the Camaro Mullet mode right now.
I switched the 29s on my Levo SL for 27.5 with similar width tires. I wanted quicker steering, less weight, and a slightly lower bike. Apart from a slight difference in trail (and bottom bracket height) no geometry has changed. I am happy with it!
My LBS reset the wheel circumference so the odometer is correct.
*Levo used to have a 27.5" version if I recall correctly.