Do VScode and Jetbrains's plug-ins /extensions satisfy your scripting needs? They're in JS and Java, I think.
Should be unnecessary (and might be outdated unless meticulously maintained) IF one chooses to just follow the VSC API docs' `yo code` approach. Which generates the project structure with a simple hello `extension.ts` IIRC.
I may give it a spin myself as I am pretty heavy user of IntelliJ.
By the way, I think Fleet, the new "Beta" editor by Jetbrains, is currently designing a custom plugin system to make it "nicer" to write plugins than for IntelliJ, but apparently it's not yet open for trials: https://www.jetbrains.com/help/fleet/managing-plugins.html