Does anyone know if you can record with Cfast card door open as this looks like a great alternative for the (at the moment) expensive Cfast cards.

DIY cheap storage for the URSA Mini cameras CFast to SSD Adapter - YouTube

Does not, this has been discussed on other boards. This solution won't work unless someone fabricates a door with a way to bypass the door lockout. It's also kind of a hack way to do it if you are a pro with paying clients as far as reliability and engineering.

Not saying it's bad but I wouldn't use a kludge like this with paying clients unless I had a lot of personal shooting with it and it had proven as reliable as CFAST. The drive reliability I wouldn't worry about, I shoot with the Ninja Blade, it's the cable, connection, power, etc. I would bite leery of. Personally, I think you are then turning the camera into something it's not, using a third party hack. Fine for a hobby but for client projects with deadlines, I would use CFast cards as you know they'll perform.

Thanks Dan.