#compose is the general channel you're mentioning already. It has a population of over 6,200 people, many of which lurk and many of those who participate do so by asking very general questions about the composition model or the compose-ui stack independent of platform. Occasionally some questions about interactions with platform-specific APIs come up, such as android arch components ViewModel or navigation. I think this is okay, and I would welcome similar questions from other platform-specific libraries because nearly all of them involve a component of the composition model and effective data flow designs that are applicable outside of those libraries that can be informative for the other lurkers in the channel.