The 27.5x3.25 Duro Crux fits the 2016 KH27.5 frame, but the 2016 KH29 frame is not quite tall enough. However, the KH29 fits the 3.0" version of the tire.
I also widened the KH27.5 and KH29 frames very slightly for 2017 (only by 2 mm), to make absolutely sure that there was no rubbing when cranking hard side to side up climbs and slightly increased the vertical clearance.
Here is the vertical clearance from hub centerline to underside of crown, and horizontal clearance at the position of the widest part of the tire:
2016 KH27.5: 380.5 mm (vertical) and 94 mm (horizontal)
2017 KH27.5: 383.5 mm (vertical) and 96 mm (horizontal)
2016 KH29: 391.5 mm (vertical) and 94 mm (horizontal)
2017 KH29: 401.5 mm (vertical) and 96 mm (horizontal)