Hey, first thanks for the thoroughly useful plugin!
I'm trying to convert my site to use the FORCE_SSL_ADMIN system so that the admin will go through HTTPS and be more secure. Part of this involves making sure that all content on the admin side is loaded over HTTPS instead of HTTP, because otherwise browsers generate "mixed content" errors.
The good news is that it's easy to automatically support this by using the content_url() function in your plugin when generating URLs that lead to the wp-content directory.
In the Alkivia framework inside capsman you are using the old system for generating URLs using WP_CONTENT_URL (/capsman/framework/init.php). This was the best-practice in the past but unfortunately there is no way to get WP_CONTENT_URL to support https. The only solution currently is to use output buffering on the entire page which is a nightmare.
So could you please update your plugin to use content_url() or plugins_url() instead? Thanks!