Because the Script Selection toolbar constantly floats around, with buttons changing as you edit, trying to avoid accidentally clicking the wrong button feels like a game of Mine Sweeper. This noticeably slows down the editing process.

Also, the fact that certain buttons I never want to use (e.g. Regenerate) sit right next to the ones I use quite frequently (e.g. Correction) make it practically impossible to develop muscle memory for the app.

Solution: Give users the ability to customize the Script Selection toolbar so they can disable or hide buttons they don't use and only leave the ones they use regularly.