Just an idea.
Today most new high end cameras have dual memory card slots that offer redundancy.
If one card goes bad the other still works and saves the day.
So how about a special CF card for single slot CF card cameras, like MF backs.
A CF card with a built in SD card adapter. Not a simple adapter, but a CF card with CF memory and a SD
adapter that can take an SD card. The CF card would pass on the data to the SD card.
This way you would have the same sort of redundancy as a modern two card DSLR.
If could even be designed so that the SD card could not be formatted without being seated directly
in an SD card reader thus avoiding most accidental formatting problems.
Now that said CF cards are remarkably robust, but being so if they do fail it's a real disaster.
It's also important to keep in mind that cards can fail when being transferred to a computer.
Also there are already special SD cards that are even waterproof.
I have had two CF cards fail. It was lucky that they did not fail at a CRITICAL MOMENT.
I nearly always shot each situation of two separate cards or at least moved the files to a computer with raid before moving
on to another situation.
While this would give MF backs, even older ones, similar redundancy as newer two slot DSLR camera I think the market for such cards would go beyond
the MF market. I mentioned this to a Hollywood sound guy and he said he would love it for some of his compact sound recorders.