I was able to fit some time in to write some code to add a shortcode [post_terms] that can handle Custom Taxonomies. The old methods, [post_categories] and [post_tags], remain the same, but the [post_terms] method has a few more configurable params to handle various conditions, and it can handle the default/built-in taxonomies.
I will be making the version changes public for download/update within 24-48 hours, or possibly sometime next week depending if I come across other changes I need to make. If you would like to download it now, the changes are currently public on GitHub Master.
I was tempted to add more params, like OrderBy, but I was afraid it may become too confusing to others, and can already be achieved by much more suitable method ,[php_function], for tasks like sorting by ‘number of posts’, ‘number of views’, and other custom values. Plus, the built-in WP sorting method doesn’t provide enough simple params for useful options to handle what the WP ‘meta-value’ param can, which almost always requires a few lines of PHP code to be added, given its complex and extensive usefullness.
I was wondering if you would be inclined to give some Feedback on whether or not I should keep the ‘max’ (Amount) and ‘empty_message’ (Exit Message) param. I wanted to add some of the useful settings that Preset Post Lists use, but keep rethinking whether it’s even worth adding. Particularly the ‘max’ param (perhaps even ‘list_amount’ or ‘amount’), which would prevent a list from potentially adding 100+ terms from the taxonomy. Right now it’s in the Development stage, but the decision will be made final with the version release candidate.