360 Images Resolution, format and viewer

Hello there!

I have looked around for quite a while but I couldn't find an answer. There are similar topics but they are old or unresolved... Sorry for bothering you again with this...

What is the maximum resolution for a 360 spherical equirectangular image for being properly loaded and viewed in a Quest 3? 2:1 8192? 12k? more?
I am referring to simple spherical panoramas, monoscopic... digital architectural renders in my case.
Should I load them to the internal storage of the Quest 3 as jpg, png, or another format?

Is the native Quest 3 viewer a good way to watch them or does it compress the files?
If so, can anyone suggest an alternative app?

Thank you in advance guys... Have a nice day everyone

Filippo