As it turns out I have a project that demos Java instrumentation, which I have tested out debugging in IntelliJ. Breakpoints work. You can use it as a reference.
https://github.com/noahlz/weaver-demo
Sample run/debug configuration from IntelliJ
Also, if you are debugging remotely, the premain might be executing before you can attach to the debugger. Try changing suspend=n
to suspend=y
in the debug command you are passing to the JVM running the agent code. That way, it will wait until you connect with IntelliJ before proceeding.