It hasn't been a week yet.
Also, I understand that you're frustrated that Integer mode doesn't work with your new Mac Mini. But, as was pointed out above (and in many places elsewhere), Integer mode is about API efficiency, not playback quality. If it doesn't work, turn it off.
And, you seem to be of the opinion that you've "proven" that MC doesn't work in Integer mode with the current gen (radically different from previous generations, I'll add) Mac Mini's. That may very well be true, but you haven't proven that. Perhaps you've proven that it doesn't work with your Mac Mini, as currently configured. But your sample size is one.
Unless you've purchased and tried it with a dozen Mac Minis, all identical, and tried it with fresh software out of the box and nothing else added. If so, I'm sure JRiver would be interested in your test results.
Until then, it is an interesting and unfortunate data point but:
* It does not impact sound quality.
* We cannot know whether you have a "special case" in some way (conflicting software, hardware that doesn't work with the Mini hardware, a hardware lemon in some way, or a driver that doesn't work with that hardware from the DAC vendor).
There are way too many possibilities.
But, as Jim said, wait a week, and maybe they'll have something new to try. It's been 6 days since he said that, and tomorrow is Friday (and they often release new public builds on Fridays). Maybe not. Maybe something unexpected is broken and they have to delay. I don't know, for sure, what Jim was telling you to wait for. But... I fail to see the urgency.