I implemented Home Connect Alt a few months ago, and have some advice for others. But if something I write is naive or wrong, please correct.
The Home Connect Alt integration works much better and much more reliably than the default Home Connect integration. I only switched when Home Connect broke for me (I have thermador appliances). I especially like that HCA reports the oven temperature.
I repeatedly hit the limit on API calls, which shuts off the service for 24 hours. I think I have finally fixed the problem.
The instructions suggest that if you have many appliances, like 5, you should divide them into two groups, install two sets of credentials, and split the appliances across them. I only have two appliances, so I tried splitting them across, one in each. It is very easy to create additional credentials so I made four and can switch them out.
In the end, I think what was causing the block was this. I have two tablets, each of which has a clock, that show HA 24-7. To make a clock inside a custom button card work, I have the line:
triggers_update: all
So I think what was happening was that the clock was triggering the subsumed HCA card to update every minute. This is 1440 calls per day, so around 6PM it would reach 1000 and trigger the BLOCKED state. What I did was separate HCA card from the clock card so they were not in the same vertical stack. This change meant the clock no longer triggered an HCA update, so it updated less frequently, staying under the cap.
This change seemed to resolve the problem and let me keep the temperature on the front page of HA.
I still have the two appliances separated, so that if one hits the limit, the other can continue to work.