Hoop
(Hoop)
22
Most reflectors are not particularly tall relative to the diameter, so the spill angle is pretty wide, but there is still a sharp cutoff like you say:
Taller reflectors have a steeper spill angle:
I think a small optical component could be glued to the center of the glass to create diffuse omni-directional spill. This would be worth experimenting with to fine tune the beam of reflector lights.