Cary SLI-80 with 4-ohm setting

Can I "break the rules" and use my Cary SLI-80 with a 4-ohm setting with 8-ohm Silverline Sonata-III speakers?

I tried to set the impedance at 4 ohms and found the sound to be more relaxed than with the 8 ohm setting, though with muddier bass.

I will appreciate any comments and opinions of Cary SLI-80 owners who had similar experience.
I had a SLI-80 F1. I think you use the taps that sound best to YOU. None of this is etched in stone.
So I do.
Yep, I do that with my Cary SLI-80 and Silverline Sonatina II's. I use a REL sub also, which you might not need with a Sonata.