That brief warm up is still an issue for lighting HIDs quickly in high beams. In the case of the H4s in my ST1300, the bulb would move back and forth to place the arc in the position of either the low or high beam. There were guards/shields to direct the light. Worked well. In the case of both my Super Ténéré and my Ford Mustang, the projector housing moves a shutter to direct the light for high or low. The Yamaha only uses a single filament incandescent bulb as OEM.
An HID arc more closely approximates a filament than an LED because it shines out at 360° and can be closely located and centered where the filament would be. The source however is kind of barrel shaped instead of cylindrical compared to an incandescent lamp though.
LEDs are the wave of the future with OEM designed reflectors to accommodate them.