Wasn't there some suggestion that the band had a fairly heavy hand in the Moving Pictures mix? I think Richard's mix of Trapeze: The Collection shows his ability in a much more favourable light. I don't think it's a given that he is not capable of delivering a top-notch 5.1 Rush album.
You're absolutely right, so allow me to rephrase:
I know it would never happen, but my fantasy is that RUSH decides that they're not up to the task of mixing 2112 and/or Hemispheres and asks Steven if he would consider doing it.*
*As stated, this is just a fantasy. Based on this article,I'm fairly certain that Chycki has already done 2112, it just hasn't been released yet.