What are the benefits of using a bike light with an adjustable beam pattern, and how can riders optimize their setup to maximize visibility and safety on the road? Are there any specific scenarios where an adjustable beam pattern would be particularly advantageous, such as navigating through urban areas with varying levels of ambient light or riding on trails with dense foliage? Can an adjustable beam pattern help to reduce glare or improve peripheral vision, and are there any notable differences in performance between lights with adjustable beam patterns and those with fixed beams? How do manufacturers typically implement adjustable beam patterns in their designs, and are there any trade-offs in terms of weight, battery life, or overall cost? Are there any emerging trends or innovations in bike lighting technology that could potentially take advantage of adjustable beam patterns in new and creative ways?