I have two separate servers running v6.9.2.
I just played with the ProCurve and was able to get the LACP ports set to passive. I set Unraid to 802.3ad and watched it change back to active-passive. The logs show the "no 802.3ad response" message, but the switch is showing a successful LACP connection. I finally found Ubiquiti commands to do the same, and it also appears to be functional. The uncertainty on the Unraid side worries me a bit, as it never really indicates that 802.3ad is correctly configured. I guess I'll let it run for a bit and see what happens.