There aren't any tests I know of. The counter functionality is really bad (the JMX methods return HTML blocks which would have to be parsed) and Adrian continues to threaten to remove it.
I have ported it anyway.
I have made a few changes along the way. There was one biggie where the counters are updated as every message arrives at a destination. *slow*.
I have changed this so instead the counter queries (samples) the queues every x milliseconds and updates itself appropriate - so it shouldn't be a bottleneck.
Actually, I shouldn't have said it was very bad, as an HTML table is pretty nice for say, an operations team to view from the JMX console, but it doesn't really work in any other context, namely for machine parsing or putting it in a spreadsheet. It would be much more useful to have something like an XML element that could be more easily transformed.
Something that should be fixed is that historical continues to accumulate in memory, and older data should be removed after some time (say, a month). And I believe the default configuration should have this set to a reasonable default.