I am glad to see another Resolve user here and even more that you solved the problem :) I have absolutely no issues with Resolve and rendering in full speed. But if someone asks me, I can help him now thanks to this video :) I personally got a quiet powerful graphics card for a notebook and I guess that is why I never had problems with the render speed. What if you try to record and render in 30fps? Your type of content doesnt really need 60fps in my opinion and you can save some more time.

One little thing: I always render in Quicktime -> MPEG since I had pixel failures with fusion compositions in my early days using mp4. Perhaps that could make a difference too for you.

Peace!