After about 2 weeks exclusively on Poloniex, I finally saw the first reports indicating that I am providing liquidity. The most recent logfile recorded a long sequence of these:
2015/09/18-15:24:35 ERROR: submit: server response invalid
2015/09/18-15:24:37 DEBUG: /liquidity: server response invalid
In the ~24 hours since then, my client has given a succession of reports all with non-zero balance and non-zero rates. I haven’t changed anything in the configuration and I don’t have a large stake; just testing at this point.