How to access one-off record data?

I’ve got one issue now solved, which I’m still sharing because others might have the same problem, and one that I’m still struggling with.

The now-solved issue: how to find one-off records once they’re added. The Help page says they’re under the Trap Records tab, but I couldn’t find them at first. The search field to use is “trap type” and scroll way down to select all the “one-off record” options that apply.

The issue that I haven’t solved yet: is it possible to associate the one-off records with a line, as you can for normal traps, POIs etc? I’d like some of these kills to be included in my line reports, but as far as I can see they are only showing up at project report levels. (It would also be easier to find the one-off records from my sub-area if I could filter by line.)
In one project-level report the one-off records were included under ‘no line’, but ‘no line’ wasn’t part of the Line dropdown list for the line reports I tested, so I’m unsure how best to view reports of one-off data in the future once there’s a larger dataset.