That doesn’t really look like a solution to the problem - RDG is seriously advanced stuff, way above the capability of many users. I’m sure I could work it out but no doubt it’ll take a few days or weeks to get up to scratch with it. From a user standpoint, gaussian was a simple, useable method for just blurring the screen. I don’t feel like you should have to dive deep into rendering code to make that happen.
I’ve looked over the RDG presentation and I’m still none the wiser about how to recreate Gaussian DOF. It’s increasingly frustrating that Epic chases “physically accurate” rendering, at the cost of existing features. But tbh I’ve been moaning about this since 4.14. I guess it’s off to RDG…