Ahh I see what you mean with the slider, what I was thinking is that you control the lights normally as you mention below for uniform colours, but then for effects you just add in extra buttons in the DTH to trigger specific scenes such as fade or police sirens for example, you’d just need a way to differentiate if a colour or a scene is then being passed.
Similar to what they are doing here with non addressable:
The main issue getting ST to try to emulate those and handle each bulb individually is you can’t just leave ST in a loop, it’ll exit after 20 seconds run time. But I do like the slider approach to at least set ranges of bulbs!