The wall:
i tried reaching out to Reddit for some help on this. they have been extremely helpful but still haven't found why this comes to a near hault. at first the cache dump just simply wasn't working. (until i pulled the drives and formatted and tested them individually) the cache drive filled up and that was it. the program kept trying to fill the cache drive but since it was 95% full it slowed WAY down. i tried some suggested settings like disable parity drives until the data is moved on, as well as Tunable (md_write_method) set to reconstruct write. that seemed to have speed things up for when it was working (i also tested without the cache drives and this speed it up from ~100mbps to 240mbps) however, there is still a brick wall i hit after a while of copying. i thought it was thermal throttling, i was getting some thermal errors on my M.2 so i got a heatsink for it and it keeps it in the "orange" and no longer blasting out 60 degree warnings. when i click "move" the M.2 dumps the data to the mechanical drives pretty fast which is great because at first it wasn't...
pepople have mentioned that it operates at the speed of the slowest drive so i did speed tests on my drives. here are the results.
I'm also including a diagnostic log. if anybody is able to help me get this going it would be much appreciated.
Diagnostic log: https://drive.google.com/file/d/1FcEHWmVRFQcwyXHxUk-PCY7IrMPH1rg4/view?usp=sharing