Reflection and normal map quality in MS Edge (WebGL)

When opening my build in MS Edge, reflections look blurry (they are sharp in the editor, firefox, chrome, opera.
Now I understand that Edge falls back to WebGL 1.0, but that does not explain this huge quality loss.

Apparently it's a known issue:
https://issuetracker.unity3d.com/issues/webgl-edge-cubemap-reflections-blurry-in-microsoft-edge
however this says it would be fixed since 2018.2, I am running 2018.2.3f1, no difference to 5.x.

If I use graphics emulation WebGL 1.0 in the editor I do not see any difference whatsoever, am I missing something there?

Since the MS Edge team says: WebGL 2.0 support is “under consideration.”, it would be nice to find a different solution rather than waiting for MS to catch up with their browser features (I think we all know how that usually turns out)


Screenshot from MS edge. In the other browsers
1. the BG is white (shouldn't gamma only touch colors in between, but excluding pure black and white?)
2. The reflections are sharp
3. The normal map on the cube looks decent.

It seems a bit as if textures are downsized to 128x128px.
Just in case I went through all quality levels of WegGL and set them to full res etc. No difference.
I have seen demos

 

What does Safari show (also WebGL 1.0)? Then you can narrow it down to it being an Edge bug or a WebGL 1.0 "bug"/limitation.