There are quite a few ST2 owners here. Some very knowledgable.
Maybe edit the title to "ST2 headlight bulb question" and they should chime in.
Good call. Thanks for that.
From what I gather, it sounds more like the particular headlight configuration, nothing to do with the bulb. Seems odd, though, because the low beam is pretty dim versus the high beam considering the bulbs are the same wattage.