I have found that SPC has been the "sweet spot" for me also on most IEMs. The IT 07 has been the only one that I have stuck with the pure silver over time.
Thing is though, with the IT 07 I stuck with the pure silver because they are capable of putting out massive detail without being shrill (to me), and I am getting older and have medium hearing loss above 12k. So SPC or copper has blunted the highs for me to the extent that I keep coming back to the pure silver (stock) cable. But, you and
@German Expat in Vietnam make a great case for the continuation of cable rolling....