No SD card?
No way.
No way.
If you can backup from the camera to SSD, that's a much much much more tempting option anyways. Anyone shooting video is already used to having a Samsung T7 SSD strapped somewhere to their rig. SD is handy as heck & so good to have but vastly fantastically slower & not as reliable.
Secondly, and more importantly, the lifespan of your camera is now the lifespan of the internal storage. That seems very unappealing.
They also offer two other sensor LEGOs: one that looks like a previous/heaper gen (fp) and other with high-res 60+ MP sensor ("fp L").
I like the idea.
None of that can be added. It's not an fp. It doesn't even have a hotshot and there's no EVF nor 'everything else' as add-on.
Only changeable things are L-mount lens and battery
except an SD card