Yes thats my channel, as for making a tutorial video on merging the branches. Not really, as each time I merge its very different. 4.12.5 was easy because all the integrations were already at around 4.12.5. But merging them into 4.13 is challenging as I have to make modifications to the actual integrations to fit the changes made to the engine in 4.13. However I have started and you can obtain a preview 4.13 version with VXGI from my merged thread.