We use and at the begin could not find much, so we created basically as it was for each platform, not much different.
The only thing we did was in the PR check, the first step would be see where we have changes (Android only, iOS only, or KMM/config which needs to run CI checks for both platforms).
Unit tests is a bit more, besides running the normal platform specific unit tests as you would in a normal project, we also run an extra KMM iOS unit tests too (Android runs both Android only and KMM unit tests in their task).