After fiddling with Alexa and the Hopper, I decided I don't care for it at all for that use. So the one to control a Tivo doesn't excite me either.
I've expanded the system, found a Tivo Bolt 4-tuner, 1Gb for a really good price. Swapped the Roamio Plus to the master bedroom tv and put the Bolt on my main TV. The Bolt supports 4K and actually upscales better than the TV, so I'm really pleased with that. Here are some issues that I found and mostly solved when I made the changes.
1. The Bolt was pixelating and having audio breakups a lot. Checked the usual suspects (i.e.; loose connections) and called Mediacom's tech support. They weren't a whole lot of help, but offered a truck roll on my dime if it turned out it was my equipment, or free if it was theirs. Since the Roamio and Mini were not showing that problem, I figured it would be something on the Bolt. Did a bit of searching on the web and found that a cablecard can sometimes be the issue. So I unplugged the Bolt, removed and re-inserted the cablecard and everything cleared up. Problem solved.
2. I use a Harmony Elite universal remote. The damned thing just wouldn't control the Bolt! So I took it through the 5 step 'learning' procedure which basically just figures out the code set being used. That did it, so things are working right with it. That said, the Tivo remote is a great remote and I tend to just use the Harmony to get things going and use the Tivo remote after that.
3. The Mini can select either the Bolt or Roamio, but oddly when selecting it is bassackwards! Select the Bolt and it sees the Roamio and vice-versa. No clue why that is.
4. One thing that is irritating is that there is no unified view of recordings/streams that show both the Bolt and Roamio, you have to select which one you want to see. On the one hand that keeps the clutter down, but OTOH, you have to dig around looking for a recording you know you have but don't remember which box. Not a huge deal but I would like the option to have a unified list.