No, the Nikon Z6 III is not compatible with the Transcend 700S V90 128GB.
Transcend 700S's real manufacturer-rated write speed is 180 MB/s, corrected 2026-07-10 from a previously-stored 250 MB/s that didn't match any real source. Nikon Z6 III's own product page states its SD slot requires an actual 250 MB/s write speed for 4K60 recording (a raw floor, not just a V90 class label -- this camera is a documented exception to the V-class-is-authoritative rule). 180 MB/s falls short by 70 MB/s -- incompatible for 4K60, despite carrying a valid V90 class rating (V90 only guarantees 90 MB/s sustained, not 250).
What works instead
See all compatible camera for the Nikon Z6 III →“CFexpress or XQD cards with a maximum data transfer rate of at least 250 MB/s, or UHS Speed Class 3 or better SD cards with a maximum data transfer rate of at least 250 MB/s, are recommended for recording and playback of videos with a high frame size or rate.”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)