I've been using a simple Google Sheet to track my personal inventory for a while now, and have basically all of my rarely-used possessions indexed. The biggest benefit is that I need to put way less effort into having a "sensible" organization scheme, since I can just throw something into "Tub D" and not worry about being able to find it later.
The one key tip I'd recommend is setting up your system to resolve nested containers. For example, Tub D itself might be in your coat closet. It doesn't look like this system is really set up for that, although my use case is also quite different than what it's targeting with insurance.
I really like this idea and the idea of knowing exactly where all the rarely-used possessions are. Admittedly, this is a little bit outside of HomeSheet's use case, but I'll certainly keep this perspective in mind.
The one key tip I'd recommend is setting up your system to resolve nested containers. For example, Tub D itself might be in your coat closet. It doesn't look like this system is really set up for that, although my use case is also quite different than what it's targeting with insurance.