Shader config for n64 VI filtering?

I have been messing round with shaders for n64 and I haven’t been able to find anything that accurately emulates the VI effects. For those unfamiliar, the n64 had multi stage postprocessing effects that blurred the screen on the horizontal access and applied a primitive form of AA on the edge of polygons.

I am playing at native resolution (240p). I tried using a pass of advanced AA with blur5-horizontal. It is somewhat close to the real thing, but the text becomes a blurry mess making it unworkable. A pass of FXAA gives some blur and edge blending, but also blurs the text quite a bit.

I have noticed that the mupen core seems to apply a full screen blur that looks pretty decent. I combine it with 2x MSAA and it looks 95% close to screen captures of real consoles with an HDMI mod. Some of my games run better on paralellie though, which doesn’t emulate the effect.

Does anybody have any suggestion on what try? Preferably something that doesn’t mangle the text?

GTU gives light scanlines (optional) and variable blurring on the horizontal axis. I would start there.