Failing to disable dedicated GPU with common methods. Issue with riser card?

So i've been looking into upgrading my Skylake Desktop to Mojave / Catalina, but as every sane person i'm not going to unplug it.

My issue is as follows:
Though i successfully have gotten the framebuffer patching to work i cannot get the Nvidia GPU to shut off when booting macOS.

I've so far tried the method by RehabMan found here, to the same effect as the "disable eGPU" patch provided by hackintool and the AddProperties approach by /u/corpnewt with the result that the dedicated GPU keeps on outputting until it freezes at the point where it usually blacks out for a second. As far as i think i understand this, it means the dedicated card prevents the iGPU driver from loading.

As i tried to fix it with the DSDT method i also could not find a dedicated _OFF Method for the IORegistry location the card is found in (which i determined through Windows). Could this be an issue because of the intermediary riser card?