Called CAry about this item yet?
I would.
In my Dodd 120wpc MK II monos the bias is at 0.70. I bias them there and or a touch above at .714 as they'll then settle right around .68 or .69. So the drift isn't much and barely if at all noticeable.
The Dodd config is ultralinear with two banks of two EL34. I use the CED Winged C's throughout. Tungsol 5687 up front.
Rather than go into it blind I'd sure be calling or emailing Cary first.
Mine came with the Winged'ers... I liked the sound... bought a fresh set and never looked back.
Good luck