May have found the answer here! https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/upgrade/521_N1_9a/n5000_upgrade_downgrade_521_n1_9a.html#pgfId-641664 Upgrading a Dual-Homed FEX Access Layer A disruptive upgrade causes a switch ...

Currently because of BA I have a disruptive reset - which the way I read it all FEX will reset at once?  As anyone verified or tested turning off half the FEX's since all our ESXi hosts are redundant this might work for us.