New Dell XPS Ubuntu has issues

Hello!  I recently purchased a Dell XPS Developer laptop pre-installed with Ubuntu 20.04.  I thought I was 'upgrading' from Lenovo T series laptop which did not come pre-installed with Linux but the Dell laptop has some annoying issues.

1. Screen flickers - just with normal usage the brightness of the screen changes regularly.   I found some mention of adding  i915.enable_psr=0 in the grub loader, but this did not solve the problem.

2. Restoring a WIFI network connection takes minutes from hibernation.   

3. Hibernation sometimes "hangs" infinitely.  This (and maybe #2 ) seem to be related to the buggy network driver ath11k_pci which describes itself as experimental in logs.. 

I like the footprint of the hardware but in doing some searches it seems like these are not isolated to me alone.   It feels like Dell is using hardware that doesn't have good driver support for on Linux.   My Lenovo was rock solid so it's pretty disappointing to buy a laptop targeted to devs running Linux have so many issues.

Has anyone come up with a stable configuration for the device?