I did in the end get a call from EBOX support, where a nice lady offered to help me. I’m not sure she understood what I was asking, alas, which was basically “can you see my ONT’s uptime?”. It sounded like she had at least a log of my PPPoE connection or disconnection events, which wasn’t helpful at all. Thankfully by then I’d found the problem and worked around it, but it would have been more helpful to get a reply to my direct questions in email - even if the answer had been “we can’t get your ONT’s uptime.”