Thanks for contacting us regarding your questions and for purchasing a Nucleus!
Let me see if I can answer your questions here:
Q: The Nucleus will be connected to a Denon receiver via HDMI acting as both core and endpoint.
A: If the Denon is being connected directly to the Nucleu’s HDMI port it should work (provided you have the zone set up correctly in the Roon App), but if the Nucleus’ HDMI output is routed through a Control4 Video Matrix before reaching the Denon then this kind of setup is not possible right now. There is currently some work in progress regarding improvements to the HDMI out from Nucleus when feeding it through Video/Audio switchers.
Q: Will the driver work with C4 EA1 and the C4 260 remote?
A: I am not aware of any hardware limitations on the EA1 or the 260 so I would expect it to behave very similar to the EA3 and T3 touchpanel we have tested in-house.
Q: I assume I’ll have no problem playing FLAC 5.1 files?
A: This will work as it currently does in Roon. If you are able to output HDMI multichannel via Roon directly, there should be no difference while using the Control4 Driver.
Q: I assume ill be able to control the Denon receiver volume while the Roon driver is active?
A: What is the current control ability in your Roon Core? You will have the same kind of control on the Nucleus that you have on your current Roon Core PC. You should be aware though that Control4 has a two audio endpoint limitation per room, mentioning it just in case you plan to have more endpoints added in the future.
Q: Is it easy to move from using the C4 driver to the native Roon app?
A: Yes, any actions you make in the Control4 driver will be reflected in the regular Roon app. This is because the C4 driver talks to the Roon API and forwards any commands to the Roon Core, so they will always be in sync.
Q: Any tips I should give to the dealer since this will be their first Nucleus/C4 install?
A: I would definitely suggest that the dealer take a look over our Control4 integration guide before beginning the programming. The links to the modules can be found here.
Hope this helps!