I always kind of found it interesting that specifying the size of object fitters was part of the JVM specification. This sort of seems like an arbitrary implementation detail, since the programmer will never have to know anything about it.
In this case the JEP is scoped to just the hotspot runtime. Other implementations are free to represent objects however they want.
https://docs.oracle.com/javase/specs/jvms/se23/html/jvms-2.h...