I had my 1540s on this morning running them from a Lotoo PAW S1 while bumbling around the house and still enjoy them a lot. However, going to them straight, or soon, after a session with either my SE846 or Fostex TH900 does make me wish Shure went ahead and produced a higher end version with better resolving capabilities. Back to back the difference is pretty noticeable.
I mean they're clearly not inherently adverse to putting out models that transverse the line between the pro and audiophile segments, as seen within their iem line up. Alas, I gave up waiting for this towards the tail end of last year and went for the TH900. They're the only company I can think of that is well regarded in the headphone world that haven't come out have what could be considered (in the headfi realm) TOTL over-ears - both open and closed.
It's been evidently demonstrated for a while now that there's an appetite for these headphones, even in their primary target audience, the pro market. Who knows, maybe they are quietly working away on something in the background...