I'm thinking I could adjust the stem, bars, grips and seat a bit on the -057. I could shorten the stem down by 20mm, to 80mm, get a set of low rise bars that are a bit wider, 720mm instead of 680mm, put on a set of ergonomic grips, and push the seat back about 1/2". Doing so would make the -057 closer to the Stache in terms of reach.
I rode another guys Stache that was setup completely different than mine in terms of the seat, bars, stem and grips. Frame size was the same. I wasn't a fan of his setup but it showed me just how different two bikes can be with just what seems to be minor differences in those few parts.
However, the biggest difference may still be the HUGE difference in how smooth the ride is with the plus tires. I just don't seem to nearly as much fatigue in my lower back as I do on the IP-057. Much less than I would even get on my FS Chiner. Patrick C tried installing a set of 27.5 wheels with 2.8" tires but clearance at the chain stays was nearly zero. Not to mention, I've ridden some 27.5x3.0 bikes and the ride is only slightly less harsh and grip is only slightly better than my -057, not nearly the difference the Stache has.
Also the picture shows there is an extra inch or so of bottom bracket clearance on the Stache which helps explain why I have only had 1 pedal strike in 200 miles of riding so far.