Having recently participated in two events that had active backchannels I'm very interested in what's happening and my mixed responses. I find it quite strenous to split or share my attention in the way that seems required to listen to a presentation and read and write in a chat. I think I could learn to do it, but not certain that I want to.
My colleague orcmid has written about the social costs of backchannels (Backchannels: Is that a dagger I feel behind me?) I agree that we need to be aware of the kind of meeting norms we're building. But what concerns me more is the personal and possible intellectual cost of learning to be attentive in the ways CPA is described. I wonder if what is lost is the learned ability to focus deeply, and in a sustained manner, on one thing. Some activities require long-term attention. For me these include reading philosophy and mathematics as well as writing software. I worry that losing the ability to single-mindedly focus is a substantial loss to our ability to be present to the world, to our work, and to our lives.