I have ADHD, and this is how I use Slack too. Works wonders and makes it manageable.

Another thing I've found useful is just leaving channels where I find little to no value. If there's something important you need to be involved in, 99% of the time you'll get added back and can catch-up to contribute. In my experience with Slack, you end up in channels for "visibility" on things that have no impact on you and you have no impact on.