I came across this awesome awesome Google doc of a lot of the famous cycling roads in Taiwan.
Unfortunately, it’s all in Chinese, but with some Google translate, I’m sure you can get through some of it.
The creator has a great graph showing you whether the route has waterfalls, night view, mountain view, and even hot springs. As well as gradients, distance, distance uphill and so on and so forth.
Feel free to leave any questions or comments you might have here, I’d be more than happy to help if I can.