Best Sonos ZP-80 Mod?

What to point your attention, that Rick Cullen's mod upsamples from default 44.1kHz to 96kHz (or 48kHz - worst case possible). Audio degrades from such resampling unless it's done properly.
I would prefer to have 44.1kHz output.

For about a month already i am enjoying Sonos with Pace-Car. My device has Ultraclock inside and WBT Nextgen as SPDIF output connected through Stereovox XV2 to Chord DAC64. I must say what Pace-Car does to my system is magic.
Chord has RAM buffer with 3 settings: off, medium and large. Common rule is to use medium or large buffer, then DAC averages digital sources to some level. Even pretty expensive Chord Blu transport is usually used with medium or large buffer.
But with Pace-Car best setting by far is BUFFER OFF. Music is smooth, focused and alive. I used to think that my system produces very fine soundstage - wide and deep, good separation of instruments. Now everything is much more real, microdynamics is better.