Innuos are not on this list. They run their own software and choose to incorporate Roon into their ecosystem their way. As what you request would need agreement between the two companies and the approach needs to be made by Innuos you need to approach them. Interestingly there are companies who use the same branch of software as Innuos who are on the list.
The performance penalty is no more. I seem to remember it was about the use of Mono? That has been addressed in Linux. But the very final line is pretty much what I intimated. Innuos have made no submissions to Roon and as such Roon can’t add the brand as per Peter’s request.