I purchased a used Antipodes Core to put Roon Core on. It is definitely better than running Roon Core and Endpoint on the Innuos. The Antipodes converts to DSD 512 in Roon without a problem but I have recently found Roon sounds better with this turned off. I haven't compared this set up with Experimental Mode yet.
I also have a Terminator Plus and Iris DDC and agree the combination is a bit step up from USB and using the clock out from the TP to the Iris has an amazing effect of clarity, timing and presence. Yes, it has a major positive effect on the Statements USB which I was not expecting.