Yeah, I think we intend to support these types of widgets eventually, but we can't do everything ourselves, and we certainly can't do everything all at once. So we're trying to prioritize the most common widgets and balance time spent writing widgets with time spent creating some of the next generation technologies that will open the doors to whole new classes of opportunities.
If you're looking for a great first task to begin contributing to Compose, this might be a good one. Looking at the code for the existing slider, it shouldn't be hard for someone in the community to write such a widget. This would be a great way to get started as an open source contributor to Compose, and would help provide value to everyone in the community. Then we can focus our efforts on getting the rest of Compose ready for a public stable release, and together we can accelerate the timeline for everyone!