Thanks @proverbian for the feedback,
Would this feature request cover your use case: https://mattermost.uservoice.com/forums/306457-general/suggestions/9982719-single-channel-guests-for-non-team-members
If so, I encourage you to upvote the feature and participate in the discussion - our team regularly monitors the Feature Idea forums https://mattermost.uservoice.com/forums/306457-general