With the AOT cache, you can actually modify the classpath (or module path as is now used for modern applications) after it has started up. The names and classes for the APIs are different, but you can still load jars at runtime even with the AOT cache enabled and functional.

The AOT cache compatibility issues come when your boot module path differs between training and actual run. As long as that is not the case, you can use it without problem and load additional modules at runtime after it has started up.

With GraalVM, that is not possible. It still has the closed-world assumption.