I pinged Mark for an update and got the following information. First, the filters are indeed the ESS filters as used in other devices with ES9028/ES9038 chips.
I didn't get into the prospect of ESS being influenced by the proprietary Reseonessence filters used in the original Invicta... but that's a definite possibility. I think it's probably difficult to separate which IP began at ESS and moved to RLabs, versus the other way around, considering designer Dustin Forman was responsible for so much on both sides. If his work on the Invicta filters informed his designs for the next gen of Sabre chips, there really wouldn't be an easy way to know for sure (I try to refrain from bugging him whenever possible). Also there are other folks involved in both firms so who knows for sure.
In other news, Resonessence Labs has a new streaming playback device launching shortly. Sounds like it is 99.9% complete, just waiting for extremely minor aesthetic details to be completed. The name is Fluvius, from the Latin term "Flow", sometimes spelled by Mark as Fluvious (because Canada, eh?). All I know so far is that it will sell for under $2k and it will be Roon certified. Hope to have more details and possibly some impressions soon though.