Purely speculation on my part - perhaps someone from Jolla can step in.

There are hardware or maybe even just firmware issues that may be in play. The physical card reader is obviously no different between SD and SDxc but it has been known that some host controllers do not support SDxc.

I would think it unlikely that Jolla would pick a host controller in the first place that didn't allow access to SDxc cards, even without exFAT support, unless there's something about the Intel tablet hardware they're using that doesn't support SDxc unless it's specified as part of the build and switched on in firmware after licencing from SDA.

The other thing I guess is that people* might want to read the SDxc specification and what it says about filesystems and FAT type systems in particular as well as the expectations that are placed on the OS and the host controller that relate directly to the structure of the filesystem and card with respect to timings and placement of things like allocation tables in particular locations. It's quite a complex document but 'FAT' appears all over the place in it, almost like the designed it with that in mind.

If you had the luxury to build a card, controller, specify the filesystem and the OS interaction with it then this debate might make sense. Presumably that's what Samsung are trying to do with f2fs. But until that is ubiquitous we still have the legacy of the SDxc standard and devices that use it.



* I'm sure somebody reads standards documents.