Re: Max image size?
If you created a parent theme and your subsites have child themes based on parent theme, add this to parent theme’s functions.php file
`<?php
/* force max-width for images and embeds */
$GLOBALS = $content_width = 600;
?>`
change 600 to whatever image size you want. This will override whatever number you set in individual sites’ Media settings for “Large”
As for implementation for all different themes within your installation, you could create a new file `my-maxwidth.php`, paste the code given above there and upload to mu-plugins folder. Make sure that the width you add there is good for all the themes you have allowed for use of members in Super Admin > Themes.
