Usually I’ve found that fine-tuning a thrower ends up being largely a matter of loosening the bezel slightly, maybe slapping the light around a bit, and tightening the bezel. The focus typically changes slightly while turning the bezel, so the last bit of tuning involves knowing when to stop turning.
If the focus is close enough that this sort of thing matters, though… that means it’s already focused pretty well.
IIRC, my K1 had a slightly imbalanced corona, but I simply twisted the bezel a little and it changed to a nearly perfect circle.
The D1S was in a class of its own when it came out in terms of being as compact as possible while keeping the 50mm head size. Then the lumintop GT mini came out with very similar dimensions.
I might like to see the updated D1S keep the 50mm head but be made for 21700 cell. This would make it unique again and give it a power/runtime boost.
Perhaps you can get hold of Boost HX leds, KW CULPM1-TG, the 4040 version of the W2, it can be driven a bit harder for some more output with the same die dimension.
I find it totally unnecessary to stress over the beam profile at close range when it’s a long range light. Perfect or slightly off at 8’ will be completely irrelevant at 5280’.