I think you should be quite good with the current state, while using SPI interfaces feels more natural it’s mostly form over function at this point because your use-case does not require it (you just set/override configuration, you don’t add any custom sampler or anything that requires custom code).
There is another option that could also have been used in your case to simplify things, if the application is deployed as a “single-jar” executable (and out side of an application server) you could also have used runtime-attach to bundle the agent binary directly into the application, the wrapper in this case could be either:
- a standalone library that sets the environment variables
- a wrapper that does the same and then delegates to the original agent attacher
However this approach also have a few limitations, in particular it makes the agent part of the application dependencies, so if you have long and lengthy validation process it could make updating the agent harder, whereas if it’s “outside” of the application you can consider it as part of the JVM/runtime and thus deal with updates on a different schedule.