Being up front with it without giving a reason has not gone good for me so far, but maybe I just need to fabricate a reason that is relatable and somewhat true. Maybe it would be ok for people when I tell them: text-only because I don't want to sink time in long meetings. Maybe its worth a shot.
Letting the client know I will reach out frequently and they can as well would also give them ease of mind and trust. That's good and I guess establishing and deepening trust is the main issue why a lot of people rely on calls/video. In my experience text is often more efficient but not preferred, but that might be because of my own problems.