So, it seems there are a few wrinkles.
I don't know if it was before, but now the /data partition is encrypted.
We don't want/need access to any "secret" data on that partition, but it's the only partition big enough to hold an update.
Code:
# mount -t ext4 /dev/block/bootdevice/by-name/userdata /data
mount: '/dev/block/bootdevice/by-name/userdata'->'/data': Invalid argument
(Note: we don't need the "su" command because we're already su and that command does not exist anyway.)
I'm looking into this...
Edit: If you're ok with wiping your data we can do that. That will work.
Do you have a Type C OTG adapter? We could use a flash drive, but you'd have to use some automated process.