About Secure Boot - its the computer I have and I’m not about to replace it. I judge the risk profile as small as its not publicly visible, its on a secure LAN and its main role is to process DTV streams. I’ve not come across an attack vector via DTV streams. But I may be wrong about that! But that is getting rather off topic.
I followed the suggestion from here TBSDTV Community Forum • View topic - Red Hat Enterprise Linux 9.4 driver installation guide(5.14)
cd media_build
./patch-kernel.sh
make -j8
make install
Do you have some insight into the Makefile scripting.