Good quality anti-aliasing for 360 videos?

Hi, ive been trying to use unity to produce 360 videos. It is simply much more convenient for me than blender or other 3D packages. However, major drawback of unity is that it is either terrible at anti-aliasing or maybe im not doing something right.

This is the quality I am getting in an 8k stereo 360 render despite SMAA. TAA doesn't show any noticeable improvement over non-AA render either.

I tried recording with unity's default recorder but it wont allow me to render anything over 4k. So for 8k I wrote a custom script following this tutorial: ( https://www.alanzucconi.com/2020/05/19/360-video-unity/ ) and capturing the render renderTexture and then to a cubemap at 8k. And still this is the result I am getting.

Is it that unity simply isn't suitable for this stuff or am I doing something wrong? This is for a static video not a real time experience, so I don't mind if the solution slows down the FPS but I do need really good quality.