Need help with EGPU

Hello

hi, I can't get my EGPU to work with my NMP.
I managed to get it working a few things but connection seems unstable, I've already installed the eGPU script.

Problems I faced are
1) I cannot boot with the EGPU plugged in.
2) I can get the EGPU recognized if I plug it in after boot, but does not show up when running LUX mark.
3) Overall I just can't get it to work consistantly.

I have the Akitio and also the R9-390x

Any general tips to help me get it working?
thanks.