Adam Mosseri just mythbusted a rumour about Instagram reach and using 3rd party editing tools for video.
So if you use TikTok to create and edit a video, or Capcut, Mojo, Opus Clip, In Shot or any other editing app other than Reels or IG Edits as long as there is no watermark (word mark) you are not going to have an issue posting it on Meta.
The more you know...