I have a Roamio with my control 4 as well. I am currently using the IP driver.
Have you figured out a way to get the zoom button from Roamio remote mapped to a button on the HC250?
Or if not, do you know how to get back to watching a recorded show after pressing the TiVo button (which takes you to the TiVo menu?) I know that the zoom button on the TiVo remote will just switch back the video window in the upper right. When watching Live TV, I can hit the Live TV button and jump back to the video in the upper right window, but that doesn't work when watching a recorded show.
The IP driver in Control4 was done for the Premier series (I believe), but it works just fine for the Roamio (minus the Zoom button, and back button, which are on the Roamio remote but not on the previous devices).