I'm pretty sure that the folks at FAA HQ coordinate with the local ATC facility responsible for the airspace you are asking to fly in (in the case of an airspace authorization/waiver). So the responses will vary based on the local view of how to integrate your operation.
FYI I filed a request for a night waiver on January 30th. My request is not for a specific area or altitude, but I intend to fly over private property where access is controlled by the owner or their representative (e.g., real estate, construction sites, private events, etc.). I included that in the waiver along with a requirement for a daylight visit to the site and the mandatory use of a VO. On 9 March, the FAA made a request for additional information. It looked somewhat like a form letter, there was not a phone number or FAA contact provided. The below was highlighted in yellow in the response:
For a waiver from section 107.29 - Daylight Operations:
• Applicant must provide a method for the remote pilot to see and avoid other aircraft, people on the ground, and ground-based structures and obstacles during darkness.
I thought I had that covered, but I revised the text of my operational description to include the statement that the VO would assist the RPIC in scanning the area for manned aircraft and non-participating people. I also included that ambient or direct lighting required for photographing the property or event would illuminate objects and people on the ground so they could be seen. Finally, if the RPIC or VO observe navigation lights, the sUAS will be lowered to an altitude that is not more that 200 feet above the ground, structure being photographed, or landed as needed to remain well clear of any manned aircraft.
Anyway, the point is that it is like a crap shoot since the FAA is not providing specific guidance or examples of what they are asking for. In my case, something seemed to be missing, but they did not specifically state what it was. Proponents are required to literally try and guess what the FAA is looking for. This results in just too much work on both sides! I imagine that if they want further information they will call me, but who knows?
It's things like this that really make my profile pic selection appropriate!