Thanks livewire
I was using the Lil Knight BOM and the 4.7M listed is the 293-4.7M-RC (xicon) which is rated only 350v...
The KOA Speer, although listed as 700v voltage rating at mouser, if you look at the data sheet, the absolute maximum working voltage is only 350v too.
The best I could get was the CMF-60 from Vishay/Dale, absolute maximum working voltage of 500v. Do you have any model that is rated at 600v spritzer? Looked at mouser and couldn't find any that kept the 50ppm/C and 1/2watt power rating
Thanks