EVGA GTX 980 on MacPro 3,1

I am having problems with the rpmfusin nvidia drivers under Fedora 28 on a 2008 Mac Pro with an EVGA GTX680 flashed to Mac ROMs. The same card has no issues in Windows 10, macOS High Sierra/Mojave or on F28/Ubuntu bionic/cosmic under the default nouveau drivers. However under the rpmfusion nviida drivers, I get a white hyphen on the screen and then a black screen with no back lighting. While trying the recipe from https://www.if-not-true-then-false.com/2015/fedora-nvidia-guide/ I found that a kernel image built with the nouveau drive blacklisted is unable to produce video using the default frame buffer. Can someone clarify how the akmod build of the kenrel modules works in rpmfuse? In particular, does the the kernel image with the nvidia driver support get built and installed on the installation of the nvidia rpmfusion packages or upon rebooting (which would mean that the freame buffer must be used at some point)?