Systems with long time no outputs in the PV ladder

I have connected a second system (Schapenhuis) to PVO. It started at the bottom of the PV ladder of course.
I notice that a huge amount of PV systems don’t send outputs to PVO (generation = 0) any more. In another post I read that a system cannot be deleted (a bit strange in my opinion).

Or maybe the owners of these systems have decomissioned them, but still want the historical data preserved in PVO. I wouldn’t know.

Is it an option to bundle all these ‘zero generation’ systems in a separate ladder?
This would clean up the active PV ladder quite a lot.

I sent site messages to the owners of each of the nearby “zero output” systems, and got several replies, and some fixes.

I focused only on the systems with a new enough inverter to collect automatic data. I figure anyone using spreadsheets just got tired of collecting each day and postings.

Note: I’ve set my PVOutput settings to poll as infrequently as allowed (e.g. 60 minutes).

The Last Seen filter can used to remove inactive systems on the ladder.