This isn't a great solution, but in cases where I've wanted to try out Cursor on a Java code base, I just open the project in both IDEs. I'll do AI-based edits with Cursor, and if I need to go clean them up or, you know, write my own code, I'll just switch over to IntelliJ.
Again, that's not the smoothest solution, but the vast majority of my work lately has been in Javascript, so for the occasional dip into Java-land, "dual-wielding" IDEs has been workable enough.
Cursor/Code handle JS codebases just fine - Webstorm is a little better maybe, but not the "leaps and bounds" difference between Code and IntelliJ - so for JS, I just live in Cursor these days.