exFAT specification did go open source
https://github.com/relan/exfat/issues/132
docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
cloudblogs.microsoft.com/opensource/2019/08/28/exfat-linux-kernel
lkml.org/lkml/2019/8/28/827
Means that exFAT will be part of the linux kernel -> becomes part of the android kernel -> gets into the SODP xperia kernel.
exFAT specification did go open source https://github.com/relan/exfat/issues/132 docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification cloudblogs.microsoft.com/opensource/2019/08/28/exfat-linux-kernel lkml.org/lkml/2019/8/28/827
Means that exFAT will be part of the linux kernel -> becomes part of the android kernel -> gets into the SODP xperia kernel.
FOLLOWING MAYBE NOW OBSOLETE:
Add relan/exfat Check if fsck works.
https://github.com/relan/exfat/
Replace the old omnirom implementation https://github.com/omnirom/android_external_exfat Looks like an old version state of exfat.
Implementations: SonyAOSP https://github.com/SonyAosp/platform_manifest/blob/android-9.0/sonyaosp/aosp.xml#L20 SODP AOSP https://github.com/sonyxperiadev/local_manifests/blob/2382083c7c19cf8da9a51618aeb064ebbe74f5aa/external.xml#L4