[Kinnard]

Ask him! I bet he has a lot of the critical insight about what works best for him. (Maybe he's already expressing it?) And I also bet that asking him is the correct first step to integrating the insight he doesn't have. And I bet the fine details matter.

  "when Leonardo painted the portrait of Ginevra de Benci in 
  the National Gallery, he put a juniper bush behind her head. 
  In it he carefully painted each individual leaf. Many 
  painters might have thought, this is just something to put 
  in the background to frame her head. No one will look that 
  closely at it.

  Not Leonardo. How hard he worked on part of a painting 
  didn't depend at all on how closely he expected anyone to 
  look at it. He was like Michael Jordan. Relentless.

  Relentlessness wins because, in the aggregate, unseen 
  details become visible. When people walk by the portrait of 
  Ginevra de Benci, their attention is often immediately 
  arrested by it, even before they look at the label and 
  notice that it says Leonardo da Vinci. All those unseen 
  details combine to produce something that's just stunning, 
  like a thousand barely audible voices all singing in tune."

  ~ https://www.paulgraham.com/hp.html

We all experience levels of communication that go beyond sufficient or effective. There's probably a zone of virtuosity that's hard to get to but invaluable if achieved where his way of communicating best is obviously neither defective nor deficient but uniquely, non-fungibly, performant and contributive. I feel unlocking unaccessed virtuosity is the key to achieving the truly apex outcomes we all want.

Kudos to you for striving to be inclusive!

EDIT check this out:

  "Benefit: More opportunities for quiet voices
  In many teams there are a combination of voices, some 
  quieter and some more assertive. Having this diversity on a 
  team is really beneficial, but can make it hard for everyone 
  to be heard. Quiet voices can find it harder to find a space 
  to interject their thoughts, or prefer to take time to think 
  about their response before communicating it, risking the 
  topic ending before the thought is shared.

  Text communication doesn’t discriminate against this 
  difference in communication style. Everyone can share their 
  ideas at their own pace, and the reader never knows how long 
  it might have taken to put thoughts into words. There’s no 
  waiting for turns, and order is more often determined by who 
  is online when, and what time in their schedule they have 
  blocked out for messages."

  ~https://buffer.com/resources/asynchronous-meetings/

[Kinnard]

https://en.wikipedia.org/wiki/Mechitza