Yes, it doesn’t make much of a difference. Only downsampling to 8 significantly reduces this occlusion/de-occlusion issue, even if it’s not perfect. It’s from 4 and below that it becomes almost invisible, but at 8, it’s already greatly reduced. A keen eye will still notice it, of course.
I created settings to manage this under the name “Global Illumination Stability,” starting with Auto (using a custom algorithm to calculate appropriate sampling based on internal resolution/window size), and then offering options for 32, 16, and 8. It’s not perfect, but it gets the job done. Maybe if Epic improves this someday, or if more interesting GI solutions are developed and become available, I’ll switch. But for now, I’m not going to overthink it.