Still running.
The entire pool is 25TB and it looks like it is going through all of the movies (it's to the Zs right now). No SMR drives. I just added two 10TB WD Red Plus drives to the pool after having two 4TB HDDs go down separately. There was triple redundancy set for the movies and pics so I'm guessing a lot needs to be replicated. Task Manager says there is no load on the computer at all.