Tilta seems to have come up with a special accessory for Sony Alpha cameras. So a kind of SSD storage module with 512GB is supposed to be released soon, which can be used with the Sony FX3 / A7s III / A7 IV / A1 models. It will be attached to the camera like a half cage and a CFexpress Type A adapter will be slid into the card slot.

Tilta CFexpress Type A to M.2 SSD Handle 512GB
As far as we know, CFexpress Type A cards are only available with a maximum of 160GB, which would more than double the storage capacity. Although there is of course also the option of using large-volume SD cards in the card slots, these do not support all recording formats. Those who want to record 4K 10-bit 4:2:2 at 100 fps (S&Q mode) with the XAVC S-I (ALL-I codec) (250 Mbit/s) will need a CFexpress Type A card.
According to Tilta, the SSD module (which is from ExAscend according to pictures) supports a write speed of 700MB/s (which is equivalent to Sony CFexpress Type A cards). This is probably to be understood as guaranteed and consistent, since maximum values of about 852MB/s are mentioned elsewhere. The data is read out via a USB3.2 Gen2x2 port with 20GBps. The recording of all formats is supported, which a CFexpress Type A in the Alpha cameras would also offer.
The adapter weighs about 100g and is designed with a cutout in the bottom so that the camera's battery can be removed. The bottom plate is compatible with Arca Swiss quick-release systems.
The Tilta CFexpress Type A to M.2 SSD Handle 512GB is priced at (plus duties), with a 10% discount for pre-orders until 10/4/2022 - shipping is expected to begin in 2-3 weeks. The package also includes a hand strap that can be attached to the side.