We are not stripping it, and we are not ignoring it. Are you sure that you have `-XX:+UseG1GC` at the *start* of a line (no leading whitespace), and also not commented out? If so, can you share the full contents of your jvm.options in a gist somewhere so that I can try to reproduce? Alternatively, you start Elasticsearch with `bash -x bin/elasticsearch` and share the output here so that I can see what's happening?
To note, as @warkolm mentions, we do not support G1GC. However, the primary reason these days is that performance with G1GC is completely unacceptable, G1GC steals too many application CPU cycles.