Yes, the Panasonic LUMIX GH7 is compatible with the Transcend 700S V90 64GB.
Panasonic LUMIX GH7's SD slot (Slot 2) accepts Transcend 700S V90 64GB directly. Transcend 700S V90 64GB is V90 class. Clears: Motion pictures (72 Mbps, requires V10); Motion pictures (200 Mbps, requires U3); Motion pictures (400 Mbps, requires V60); Motion pictures (600 Mbps, requires V90). Above 600Mbps -- including variable frame rate with ALL-Intra and internal ProRes/ProRes RAW recording -- Panasonic's own spec states these require a CFexpress card; no SD card of any class can record them.
Limitation
Cannot record above 600Mbps on the SD slot (variable frame rate ALL-Intra, ProRes/ProRes RAW) -- CFexpress card only, no SD card of any class can do this. Works for every SD-eligible Long-GOP mode up to 600Mbps (Video Speed Class 90).
“Motion pictures with 72Mbps or less: CFexpress card, SD memory card with SD Speed Class with Class 10 or Video Speed Class 10 or higher Motion pictures with 200Mbps or less: CFexpress card, SD memory card with UHS-I / UHS-II UHS Speed Class 3 (U3) or Video Speed Class 30 or higher Motion pictures with 400Mbps or less: CFexpress card, SD memory card with Video Speed Class 60 or higher Motion pictures with 600Mbps or less: CFexpress card, SD memory card with Video Speed Class 90 Motion pictures with 800Mbps or more, variable frame rate with ALL-Intra, or ProRes: CFexpress card”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)