Well, that is not at all what I experienced. I used my MB7,1 with no acceleration for a week before I found the patch that enabled acceleration on nVidia Tesla cards. It was
hell. Dosdude1 and others have said the same, a system without acceleration is barely usable. It renders all the graphics on the CPU and has no support for transparency or 3D animations at all.
MacBookPro6,1 has an nVidia Tesla GPU. It's not one of the unsupported AMD based models. You most likely have acceleration, in fact.
I'm not sure what you're talking about with Hybrid/Flat modes but those only apply to systems
with acceleration anyways. They fix minor graphical glitches, they do
not enable transparency on a system with no acceleration.
Edit: I realized the mistake. You are mixing up graphical acceleration and the light mode transparency glitch. Graphical acceleration is enabled by kexts (taken from 10.12 (I think) for Intel and some AMD GPUs, and taken from 10.13 and patched by me for nVidia Tesla GPUs). The light mode glitches (weird grey windows) is an unrelated problem that is caused by lack of Metal but not lack of acceleration. @pkouame and others have developed excellent patches for that.