Most reflectors with a biased diffusion to the left or right are older OEM types. This was done at one time to keep the lamp from looking crooked on the front of the bike when it was aimed correctly.
Since the language of most lighting laws reads somewhat vaguely, like so:
A lamp identified by Subsection (a) shall produce:
(1) an uppermost distribution of light or composite beam that is aimed and emits light sufficient to reveal a person or vehicle at a distance of at least 450 feet ahead during all conditions of loading; and
(2) a lowermost distribution of light or composite beam that:
(A) is aimed and emits light sufficient to reveal a person or vehicle at a distance of at least 150 feet ahead; and
(B) is aimed so that no part of the high-intensity portion of the beam on a vehicle that is operated on a straight, level road under any condition of loading projects into the eyes of an approaching vehicle operator.
It's pretty common for lamps nowadays to have an effective diffuser relative to the lamp's usage (hi-lo composites tend to cast a narrower beam) It would be nice to find a dedicated 55W lo and 60W high with reflectors optimized to each beam, but I imagine that would be pricey. Running a pair of lights that were composites would require a significant amount of juice.
Quick side story- The older Yamaha Road Stars have sufficient charging systems, but not a lot of surplus power. The accessory passing lamps come with 35 watt H-3 bulbs in them. Many a dead battery and housing/wiring fire has passed due to folks putting 55 watt bulbs in these. It's just not made for the extra heat. Many have said, "it's just 40 watts" Maybe so, but when you consider (and tell them) it's a 63% increase in wattage on 2 lamps, it seems to get their attention better.
Have you considered LED or HID? A rack of lamps wouldn't be that difficult to make up with some parts store 5 1/4" assemblies, although they would be singles, and you'd have to run one high beam and the other low to be legal most places. You might check aftermarket H-D parts for a pair of dual filament 5 1/4" units, but I'd be certain about capacity before I though about running a pair of lamps. My SV650 will barely support a pair of 60 watt lamps with about 15 watts or so to spare.