Try without the SELinux patch to permissive; disabling verity wouldn't hurt for the testing either, did you do that as well after disabling SELinux? Do you have the correct OEM libraries installed: ( https://androidfilehost.com/?fid=6006931924117907560 ) ? I will go over the boot again and see if somehow I wrote in the line for treble to be enabled incorrectly (don't believe I did, but will look). If @Sjll would reply to someone we might be able to get an updated tutorial for 10 and 11 treble.
Yep using the right OEM. Tried setting selinux to both permissive and enforcing. Disabled verity right after as well. Will keep trying to see in case I overlooked anything (it's easy to miss a step when you test so many combinations).