Hi Jack,
Not your question - but ditch the MP3s and subscribe to Tidal or Qobuz. You;ll get at minimum full FLAC ro HD, and a huge library. You simply cant get good meals from poor ingredients
As to ASR - they measure. I guess you;ve been in a cave (*maybe wise) but this topic comes up regularly. If you believes measurements no one would spend more than about $100 for a DAC and $300 for an integrated amp. No tubes (terrible measurements). Certainly no vinyl (60 dB SNR). I wont open Pandora's box (what are they missing?, do we like accurate) - but reality says otherwise.
Oh, and I design this stuff professionally as a side hobby, and retired as CTO of a major tech firm, so not unfamiliar with the tech. I sure wish measurements did correlate - my job would be much easier.