Hi @LeoColman,
Sorry I don't have ans for ur question. I didn't find any alternative for JaCoCo.
Even we are using JaCoCo to get the coverage. But lately for JDK 8+ we have started facing test cases failing issues, which runs perfectly fine when u run through the Android Studio.
We tried multiple solution like Android Orchestrator but it didn't solve the problem.
Even if u have faced the same issue, then it will be very helpful if u share ur insights.