That probably needs to be changed, with some distinction between “Home Data” and “Device Data”. But most Sense users seem to forget that the everything they do on their phone or web app actually lives in the cloud, not on the phone. Right now, the home inventory is just part of your Sense data that lives out on the cloud. Gotta be frustrating - I understand why you feel the way you do.
ps: One more note - the device inventory can’t be saved, but if you input data on all your devices into the “Manage” tab, you can get a permanent copy of that data via a quick daily export fro a time period where everything has turned on at least once. That way you’ll at least have a spreadsheet of the data you entered