That link doesn't work, the one on the first post does.
I tried the beta build, /system read only button can be depressed now (a problem I posted before here).
It still does not mount /data on stock Oreo, I do not have a password set, do I need to set one?
It also takes much longer to load, I am guessing trying to mount something.
if it can't mount encrypted data without a password it won't be able to mount it with one. The extra time it takes is it trying to do so.