[@egyptimhotep Participant 10 years, 2 months ago]

PATH: includes/class-wp-editor.php

Line 74: elseif ( $set[‘editor_height’] > 5000 )
Line 75: $set[‘editor_height’] = 5000;

if you change the last 5000 on line 75 to a smaller number – say 300 or whatever you prefer – then save the file, the ginormous box will re-size to that height.

Good Luck