Yes that is how it works. But not all features are available through Homekit, most notably you can’t set te state for Home/Away. That can only be set through the cloud API.

Be aware Tado just announced limiting access to the Api to 100 calls a day. Which is quite low. For full access you need a subscription for 5 euros a month. Perhaps read up on that before investing.

You can configure storage paths. That way, you can direct tags to be stored in a specific folder.

You can then get the files for the accountant from your file system.

Just specify from: on and to: off in the trigger. You can have both!

I don’t know your automation format very well. My automations use a state trigger with from: and to:

Some apps have breaking changes. If you can restore a complete backup when that occurs, you can recover. Immich is famous for its breaking changes

I would recommend to avoid Scaleway. They simply lost part of my files in the first week. Were very unresponsive and in the end could not recover. Pretty much everything you are hoping to never encounter with a storage provider.

I have had a lot of fun setting up Unraid. It has everything you are looking for. It does cost some money to start, but was very much worth it to me.

Don’t forget earplugs when visiting a concert. Prevent tinnitus, the ringing in your ears for indefinitely.