I’m running three WiiM Pro’s across three systems of different caliber. The biggest bottleneck of WiiM using external DAC is the quality of the digital output. Perhaps it’s jitter and/or mediocre clock imbedded in signal of the WiiM, Despite claims of superior jitter reduction of many high end DAC, I humbly believe that stand alone DDC does much to improve the sound.
i personally feel that Denafrips Hermes and IFI Spdif help extracts the best from WiiM. It did justice in my systems running Berkeley Alpha, Terminator II-12, and PS Audio PerfectWave DirectStream Mkii.

