Unless I’ve misunderstood, you have to maintain the list of allowed content types, and the snippet template used to display each one, in every manual slot. This is something that is easily overlooked as you subsequently create new content types or replace snippet templates with new versions.
If the interface allowed snippet templates to be selected without specifying a content type, and then the system allowed any content type that was allowed for that template to be added to the slot, it would save having to maintain the list in slots. Obviously you’d still want to be able to restrict the content types in most scenarios. But for “Quick Link” slots intended to allow content contributors to link to anything in the site, it would be an improvement.
We are now implementing a dispatch snippet template, allowed for use with all content types, to hide the complexity of different templates from users of the Active Assembly Table Editor (aka Related Content Control.) It would make it even easier if slots such as sys_inline_variant could be associated with just the template, and would then inherit relationships with all the content types associated with that template.
One idea was to switch the management option to “exclude from slot” rather than “allow in slot.”
Using the exclude approach would mean you’d only have to list the CT-Template pairs you did NOT want to allow.
Note: Some of the configuration features coming in “Barracuda” may ease this (by making the configuration less dependent on the Workbench) but they won’t change the settings themselves.