steamvr-undistort VS ARCoreInsideOutTrackingGearVr

I don't know if this works with Cosmos but give this tool a try as it lets you modify the distortion parameters (for a HTC Vive) while in VR so you can observe how they impact everything. Hopefully it works with the Cosmos as well. Just make sure you backup your config file before making changes as there is no way to recover the data (at least that's how it works with the Vive) once you alter it.

You could try it on your Vive first! It's totally worth it. I bought mine from eBay, but you can 3D print adapters yourself, too. This is also a great utility for fine-tuning distortion after swapping the lenses: https://github.com/sencercoltu/steamvr-undistort

If you want to minimize your distortion you have to put in a decent amount of work by using tools like this.

It's a lottery. Every lens is different but if you put in some work and use this tool you can pretty much eliminate the barrel distortion. Pupil Swim is a different story though and that's something that is just more prominent on the GearVR lens. However, it's one of those things that some people simply don't even notice.

Sure. You can tweak depth settings with this tool: https://github.com/sencercoltu/steamvr-undistort

If you have barrel distortion, this tool will help correct it. It will even help with the factory fresnel lenses. You can adjust so much with it. https://github.com/sencercoltu/steamvr-undistort

Inside Out Positional Tracking (6DoF) for GearVR/Cardboard/Daydream using ARCore v1.6.0