I set up Home Assistant for my parents after their Insteon system turned into a brick. It did a great job of controlling everything, but it seems to think there's an extra sunset at 4:17PM every day which has made scheduling a challenge.
Looks like I replaced most of what I have with blueprints, though here’s an example of a simple blueprint that just turns something on at your specified sun elevation:
HA has had some form of Insteon integration for close to a decade. But I think a lot of the improvements in it recently has been to help new migrants from the Insteon Hub market cope.