While Taiko did use Roon, it moved on to TAS, and is now in the process of completing the very purpose-built XDMS software, which essentially all users who have it say it is easily the best software for the Extreme - XDMS is I believe not in fully finished form yet, but can be downloaded to the Extreme in I think Alpha or Beta release, with help of the Taiko support staff- it is a Taiko-built product. Likewise, TAS, as mentioned above, was almost universally preferred over Roon, on a sound quality basis. As Lalitk said, Emil, designer of the Taiko Extreme, stated that XDMS is all about the sound quality. I believe you can still use Roon on the Extreme, but it will not yield the best sound quality. And some do still use it at least part time because they love the feature-rich application.
Emil also noted that the problem with Roon is that they often release updates for the software and they are not focused on sound quality, but rather the useability of the software. From what I've read, many users, and I think server manufacturers, have provided their opinion on this sound quality issue to Roon.
As a side note, Wadax use Roon as their software interface. I believe it is a very custom set and I believe it is locked down so it can't influence sound quality. But you'd have to ask Mike Lavigne about that because he has very in-depth knowledge of the Wadax gear, in addition to being an owner/user. You can read about that here on Agon and on WBF.