Keep running out of Solcast API calls

I am running predbat with the Solcast integration. I have 2 Solcast sites - one for each of my roof elevations. My problem is that I am reaching my quota of 10 Solcast API calls by midday.
If I look at today's HA activity log for the Solcast API there were calls made at 04:48, 08:07 and 11:25


...and my "API Used" figure has already reached the maximum of 10:

I have set
solcast_poll_hours: 8
in my apps.yaml, but this seems to be being ignored. The idea was that I would make 3 API calls per day, for 2 sites.
Any idea how I can configure Solcast/Predbat to better spread the API calls across the day so that I don't reach the limit so early in the day?