golfer_LD The Synchron Vespa wasn't "based on" the Acer XDS React, it was the exact same head with a different badge in it. But from what I was told by Gineta (CEO of Hireko) this head was designed after they acquired Orlimar. And it would certainly make sense to start with an existing design that they already have and simply modify it for SL (loft gapping, weight, etc) than to design a new head from the ground up. Especially for something like SL irons which aren't mainstream enough yet to warrant the countless hours of R&D, tooling, testing, etc, to design a set of heads from scratch.
I'll try to get some real world pics side by side to compare the similarities and differences. One thing I definitely noticed is that the Orlimars don't have the little weighted area in the center of the cavity like the React/Vespa.