The instrumentation logger requires plain text files with the data on a very specific format.
With log4j2, all the files share the same appender configuration. If the format is changed on the appender, the instrumentation logger won't work.
The current appender does the aggregation on compressed files, and for this reason, the instrumentation logger won't be able to read the rotated files, inly the latest file which could have just a few minutes on big installations.
The instrumentation logger must have its own appender, to avoid potential problems.