It goes away in youtube but not in game, youtube compression actually does a better job than DSR for FFXIV.
The only thing that works is SGSSAA in DX9, its unavailable in DX11.
I have tried all the effects in the framework and nothing works at all. I have even tried silly stuff like explosion and absurd amounts of gaussian blur etc, the only way to mask it is with film grain because that just makes everything flicker if you use too much.
Anyway youtube can do it so why not reshade, see here:
Flickers in game and on 4k youtube, but playing back at 1080p it doesnt. Was recording on a 1080p panel with DSRx4.