You could write java actions for this. You'll still have to start the runtime but then you can just make a list of microflows you want to test and call them by java. An example can be found in our documentation

You could even start this action by triggering it in a microflow that runs on startup, or run it as a scheduled event.

It's also possible to do the same from a testmicroflow if you don't want to write java, you could still run them on startup.