That out of the way, I've been running high sierra without any hitches for a few months now after following this video installation guide. however after booting last night found the system to be sluggish and stuttery, which from what i can tell is indicative of a lack of gpu acceleration.
I have updated all of my kexts, including whatevergreen with no luck, I would have tried reinstalling mac os however the high sierra dmg by xlnc is no longer hosted on google drive and so I can't create the bootable media to start from square one again.
if possible I'd like to know what further steps I can take to troubleshoot and fix this issue. thanks !
Motherboard: MSI B450 TOMAHAWK
CPU: AMD Ryzen 5 3600
GPU: Sapphire RX 480 4GB