I purchased a 2017 2861DS 6 months ago and finally figured out how it is wired. I crawled around under the RV and behind panels to figure it out because I noticed that the battery disconnect switch did not do what I expected based on my previous RVs. On my previous RVs, the battery disconnect switch would completely isolate the battery but on this unit the battery is still being charged irregardless of the switch position.
On my previous RVs the converter would boil off some water over time so I disconnected the battery and used a batter tender to keep them charged. Fortunately, the converter/charger on my new Forester does not boil off any water after being plugged into shore power for the last 6 months so I feel ok about letting the converter keep it charged.
As you can see in the schematic, the disconnect switch simply removes circuits that could slowly drain the battery such as CO/Propane monitor, 12VDC TVs, DVD player, refer; but leaves a few non-draining items on the battery.
Hopefully, the attached schematic will be useful to someone and not viewed as me trying to show off. I have put it together as it makes sense to me as a mechanical, not electrical, tech.
2017 Forester 2861DS
towing 2015 Jeep Rubicon