One video idea, three platforms: what do you change before cross-posting?

A practical question about adapting the same short video idea for TikTok, Reels, and Shorts without copying every caption and CTA unchanged.

Cross-posting saves time, but the same export can feel slightly wrong on each platform. The core promise can stay the same, but the first line, safe-area text, caption, and next action often need changes. For example, a Shorts version might bridge to a longer YouTube video, while a Reels version might point to a carousel or profile highlight. TikTok might work better with a comment prompt. If all three versions use the same CTA, the idea may be reused but the viewer path is not. What do you change first when adapting one short video idea across platforms?