Have a way to set a "start" section of the script and then "end" selection of the script so that it can be deleted without using a mouse using only a keyboard.

Place my text cursor at the beginning of the section I want to select.

Mark that location as the START of the selection.

Navigate through the transcript without having to hold Shift or continuously extend the selection.

Place my cursor at the end of the section.

Mark that location as the END of the selection.

Have Descript select everything between those two points so I can press Delete and remove the corresponding audio/video.