We do not have an 8080 implementation I'm afraid. I think you'll be able to get something running relatively quickly though. TouchGFX calls a hook function whenever something in the frame buffer changes, and you'll need to implement this so it transfers the updated region to the display using 8080. This is explained in more detail in this knowledge base article: https://touchgfx.zendesk.com/hc/en-us/articles/203642951-MCUs-without-TFT-controller
You can also check out this forum post: https://touchgfx.zendesk.com/hc/communities/public/questions/201481402-Porting-TouchGFX-to-8080-based-LCDs
Maybe John has some additional tips he can share.