Should the fix work in 4.19.2? I just tried and noticed no change 
Below is the info from Dethrey’s project with the render targets. (verified that r.gpucrashdebugging is 0, ran in standalone game)
Time Since Boot: 20.23 Seconds
Platform Memory Stats for Windows
Process Physical Memory: 889.68 MB used, 926.53 MB peak
Process Virtual Memory: 1177.03 MB used, 1226.25 MB peak
Physical Memory: 5499.68 MB used, 10832.95 MB free, 16332.62 MB total
Virtual Memory: 6117.48 MB used, 10832.95 MB free, 134217728.00 MB total
Time Since Boot: 182.32 Seconds
Platform Memory Stats for Windows
Process Physical Memory: 1264.52 MB used, 1681.52 MB peak
Process Virtual Memory: 1552.15 MB used, 1970.98 MB peak
Physical Memory: 5823.97 MB used, 10508.65 MB free, 16332.62 MB total
Virtual Memory: 6473.42 MB used, 10508.65 MB free, 134217728.00 MB total
I also still had the original particle test project with the mesh emitters laying around and noticed the hitch within a minute or so.