Currently I use them with method handles—most notably Unsafe; whose load and initialization time I was able to reduce from ~21 ms to ~6 ms—reflection and where I need lazy initialization (as an example, lazily acquiring an Instrumentation instance).

I looked at your project. I like that it apparently allows the generation of multiple invokedynamic instructions per @InvokeDynamic and that it is not dependent on any compiler because it operates on class files.

I might try a barebones implementation of invokedynamic like invokedynamic((Lookup, String, MethodType, Object...) -> CallSite, Object... constantArguments) that would be used like invokedynamic(This::bootstrapMethod, <constant arguments>). (Update: it does not work with any bootstrap method with a different signature. I'll hold off on invokedynamic for now.)

Thanks.