I think there is a general question here whether we want to support UI extensions (custom scripts and stylesheets) in the JVM console. That is up to the JVM console folks to decide I think. If we do, they would need to be a distinct config from the main console's extensions, since they won't necessarily be compatible.
The current JVM console doesn't support such feature. We are planning to do a major upgrade later this year and would prefer to postpone it until the major upgrade is done.