Custom height/width for thickbox in WP Backend

I use thickbox in the WP backend for preview or other content. On own pages in the backend works my script very fine and a can use custom width and height for the thickbox. below my code:

            <script type="text/javascript">
            <!--
                var viewportwidth;
                var viewportheight;

                if (typeof window.innerWidth != 'undefined') {
                    viewportwidth = window.innerWidth-80,
                    viewportheight = window.innerHeight-100
                } else if (typeof document.documentElement != 'undefined'
                    && typeof document.documentElement.clientWidth !=
                    'undefined' && document.documentElement.clientWidth != 0)
                {
                    viewportwidth = document.documentElement.clientWidth,
                    viewportheight = document.documentElement.clientHeight
                } else { // older versions of IE
                    viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
                    viewportheight = document.getElementsByTagName('body')[0].clientHeight
                }
                //document.write('<p class="textright">Your viewport width is '+viewportwidth+'x'+viewportheight+'</p>');
                document.write('<a onclick="return false;" href="https://wordpress.stackexchange.com/questions/1659/<?php echo WP_PLUGIN_URL ."https://wordpress.stackexchange.com/" . FB_ADM_BASEDIR; ?>/inc/index.php?username=<?php echo DB_USER; ?>&?KeepThis=true&amp;TB_iframe=true&amp;height="+viewportheight+"&width="+viewportwidth+"" class="thickbox button"><?php _e( 'Start Adminer', FB_ADM_TEXTDOMAIN ); ?></a>');
                //-->
            </script>

Now to my problem and question. I will use a thickbox on the page wp-admin/plugins.php and here dont work the script. WP set the height and width always to the core-values and this is to small for my request.

Maybe other readers have an idea or a solution.

Many thanks!

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.