Interestingly, wlan2 is working much better today but now wlan0 is acting like wlan2 was yesterday. I removed wlan2 from the NANO, connected a laptop via the provided Y cable, factory reset the NANO, and then connected a single wireless client via the management network. When I ping the wireless client from either the laptop or the NANO itself, I get similar ping results. The NANO and the test wireless client approximately 5' apart.
Pinging 172.16.42.154 with 32 bytes of data:
Reply from 172.16.42.154: bytes=32 time=608ms TTL=64
Reply from 172.16.42.154: bytes=32 time=2405ms TTL=64
Reply from 172.16.42.154: bytes=32 time=4ms TTL=64
Reply from 172.16.42.154: bytes=32 time=2225ms TTL=64
Reply from 172.16.42.154: bytes=32 time=4ms TTL=64
Reply from 172.16.42.154: bytes=32 time=2065ms TTL=64
Reply from 172.16.42.154: bytes=32 time=5ms TTL=64
Reply from 172.16.42.154: bytes=32 time=1683ms TTL=64
Reply from 172.16.42.154: bytes=32 time=3ms TTL=64
Reply from 172.16.42.154: bytes=32 time=409ms TTL=64
Reply from 172.16.42.154: bytes=32 time=2162ms TTL=64
Reply from 172.16.42.154: bytes=32 time=3ms TTL=64
Reply from 172.16.42.154: bytes=32 time=1246ms TTL=64
Reply from 172.16.42.154: bytes=32 time=3ms TTL=64
Reply from 172.16.42.154: bytes=32 time=1749ms TTL=64
Reply from 172.16.42.154: bytes=32 time=6ms TTL=64
Reply from 172.16.42.154: bytes=32 time=1234ms TTL=64
Reply from 172.16.42.154: bytes=32 time=4ms TTL=64
Reply from 172.16.42.154: bytes=32 time=754ms TTL=64
Reply from 172.16.42.154: bytes=32 time=75ms TTL=64
Ping statistics for 172.16.42.154:
Packets: Sent = 20, Received = 20, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 3ms, Maximum = 2405ms, Average = 832ms