Configure MDADM to skip RAID5/6 assembly during boot IF AND ONLY IF the array is in degraded state

I’m basically trying to configure mdadm.conf so that RAID assembly at boot is run with the equivalent of:

mdadm --assemble --scan --no-degraded

instead of:

mdadm --assemble --scan

Otherwise, if I temporally unplug one or two RAID6 devices to free the SATA ports, MDADM assembles the array in degraded state on the next boot, the unplugged devices become desynchronized, and I need to readd and rebuild them, which can take a day or two.

I haven’t found anything on mdadm.conf(5) or the MDADM documentation, but I’m pretty sure this is a fairly common situation with a simple solution.