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.

So frustrating, it’s great! As a suggestion: the birth date picker should be one of those calendar popups where you are forced to browse back with an arrow to the previous month, a zillion clicks until you reach your birthdate. Of course with a slight delay between each click.

That would be torture