The smell didn't bother me quite frankly.
The cable is a bit too long when I was riding bike. But the length is actually good for me to plug into my amp for better listening at home.
There isn't a way to turn xr into sr via eq. It can match the frequency response but they will still sound different in terms of texture and vividness. They can sound close tho.
If you just want some more highs, I recommend to get a PtoS adapter for xr. That brings the highs much closer to that of sr, and that is one of my most enjoyable combination.
Does using the PtoS adapter reduces the bass of the XR too? Also what is the impedance of the adapter? Would using a 100ohm impedance adapter yields the same result as the PtoS adapter?