See first several lines in interface/forms/CAMOS/view.php file:
$textarea_rows = 20;
$textarea_cols = 40;
Modifying these will change the settings of the text area size.
Since your optimizing this in actual use, can you let us know what settings work best for you. I’ll then put these settings into the main codebase, so other users will benefit.
Tested out the settings, and modified parameters in the main codebase, but was a bit less aggressive to avoid having the scrollbars show up when using OpenEMR in standard split frame mode:
rows=22
cols=90
Since this definitely improves the functionality, plan to include in the next 4.1 patch also.