It would be nice to have a CLI tool to run against a compaction configuration to allow you to check it before deploying. There are a lot of requirements and differences between internal and external Compactable types that can be tricky and probably won't get caught until the compaction manager tries to create them as a compaction service. These would fall under the tserver.compaction.major.service property, specifically the JSON used to configure planner.opts.executors.