Yes, the Sony FX30 is compatible with the Transcend 700S V90 128GB.
Transcend 700S is an SDXC V90 card. The FX30's SD floor is V60 for standard XAVC HS/S 4K and V90 for the higher-bitrate XAVC S-I 4K -- V90 clears both.
“XAVC S-I 4K 600Mbps CFexpress Type A memory card (VPG200 or higher) SDXC V90 or higher”
Last verified:
Confidence: inferred