Did you have any luck getting the power down with the new bios.
I see that there are different 'updated' firmware versions, most have the intel 600 fix, but there seems to be a difference with hot swap compatibility. link
I have a asm1166 incoming from aliexpress. planning on using the Pro H610T D4-CSM with 2 X16 seagate HDD and ssd for starters.
I've seen you wanted to try the 92% efficient mean well, but i'm thinking more of a 15v 90W mean well GST90A. the 15v will be a bit more power hungry, but i'm hoping it will help with the initial power draw from the spinning hdd (might add more in the future) to not dip below 12V and brown out.