Do not publish the offcuts
Studio tools can split, reframe, caption, and transcribe a longer video. Use that as a first pass. Then watch each suggestion with the sound off. If you do not know what the clip is promising in two seconds, it is not a TikTok yet.
Write a new opening line. Crop for the face and the action. Remove the other platform’s watermark. Ten clips from one video is a good week only if five of them are actually good. Post the good ones.