FWIW, I recently changed out my iFi Zen DAC for a SMSL M500 (which has a faulty LCD display so it’s going back and it doesn’t have fixed volume option so I’m getting the SMSL SU-9 instead)… BUT…
I haven’t had a single “static when upsampling” issue in 48 hours and I know I would have had it multiple times on my previous setup. So it is perhaps DAC specific related.