Custom height/width for thickbox in WP Backend

by

plugins.php page calls add_thickbox() function that enqueues WP native thickbox script and style. It has this in documentation:

If any of the settings need to be changed, this can be done with another js
file similar to media-upload.js and theme-preview.js. That file should
require array(‘thickbox’) to ensure it is loaded after.

So there are different possible ways to approach this:

  1. As WP suggest create and queue .js file that will add settings you need to defaults.
  2. Re-register or disable native thickbox completely and replace with your own code.