I tested UDF and exFAT over a fairly wide range of non-computer devices, and none of the devices could read or write to it. If you need something that will work with non-computers, stick to FAT32. If you just need interoperability between computers (but don’t need to boot from the drive), switch over to UDF.
I UDF and exFAT did not work with:
I plan on testing UDF and exFAT with a few phones and will update this post when I do.