It's not hard to simulate an XR-E's naked beam pattern if that's what someone wants to do.
With a small conical collar dropped over a Seoul P4 (or other lambertian LED), something more XR-E-like can be made.
The blue curve ('collared P4') added to the graph is for a P4 with a reasonable-sized conical collar, front diameter about 13mm, roughly 90 degree full-angle, - the upper LED in:
The curve on the graph is only approximate - using a cheap luxmeter with a cardboard tube lens hood taped to the front and rotating the light by hand over a printed protractor scale, but taking readings each 10 degrees going up and down the angles seemed to give reasonably repeatable results.
With a shallower reflector, less side-light would be captured and redirected forwards, so the curve would be less centre-weighted, and a decent approximation to a naked XR-E should be obtainable for anyone who wanted that.
With one of the smaller-package recent Crees, the necesary reflector would be tiny. I have made one for an XP-E, pretty much to LED-scale with the one in the above picture, but forming and taping the reflective plastic using tweezers was desperately fiddly, and would have been rather easier if forming over a conical mould.
If there actually was a market, such reflectors should be easy for a commercial company to churn out for peanuts.
