I had the same question but the jig in the photo doesn't look long enough to accommodate wheelie bar wheel alignment.

Unless im wrong if the wheelie bars are crooked they will steer the rear end when they touch and push the tires out of line messing up tire grip.

Yes the Rgeo jig is a road course jig, but it is easy to get around this by building the main rails long & then moving the chassis around on the jig to do what is needed. I build nice rails on this jig; just takes some thought & planning...