Just wanted to leave a Big Thank You
rj510. The guide was spot on. I dropped in a GTX760 instead, no drivers needed. Not sure if I any cleanup is required of the leftover IGPU files but it works as intended.
On the initial attempt I forgot on restart to select the new Install MacOs Partition, which caused some problems, but on second attempt all good.
One thing I notice, but maybe it's a Mojave bug: sometimes the icons don't update properly: for example, when you copy a file it gets the spinner on top, but when it finished copying, it stays with the copying icon still, if anyone has any clue or has seen this before?
PS: I'm thinking of disabling the speedstep and other power saving settings (as they might impact audio latency, which was a problem on PCs), but I saw you left them Enabled. Are those required by any chance?
PPS: The USB3 Headers, HS10 and HS11 seem to work with a usb drive, but not with my wireless keyboard/mouse, any idea why? I'm thinking of disabling the 1 and 2 ports (the other header ports, 2.0, as I don't have them hooked up). What would be the best way to achieve that?