StartupTrigger in JSR-233 (groovy)

Is there a way to define a startup trigger when using JSR-233 rules with groovy?

It is not on the list https://docs.openhab.org/configuration/jsr223.html#trigger-types-all-jsr223-languages, as far as I can see.

I found https://github.com/steve-bate/openhab2-jython/blob/master/scripts/components/000_StartupTrigger.py which seems to implement a StartupTrigger for Jython scripts. I really hope there is an easier way to do this…