No, the Nikon Z6 III is not compatible with the ProGrade Digital CFexpress Type B Gold 128GB.
ProGrade CFexpress Type B Gold's 128GB SKU writes at 260 MB/s (manufacturer's own page, capacity-specific). Nikon Z6 III's CFexpress Type B slot requires a minimum 500 MB/s sustained write for 4K60 recording. 260 MB/s does not clear that floor -- incompatible for 4K60 on this body (lower framerates/bitrates not re-checked here).
What works instead
See all compatible camera for the Nikon Z6 III →“Nikon Z6 III product page: Dual Card Slots — SD UHS-II + CFexpress (Type B)/XQD; CFexpress Type B cards supported in the dedicated CFexpress/XQD slot.”
“Read 1700MB/s | Write 260MB/s Sustained write 250MB/s”
Last verified:
Confidence: inferred