Just noticed that add_custom_param_handler is not even available as a method on TopicQuery. Is there another way to build custom filters for topics in newer discourse versions?
TopicQuery singleton_methods: [:add_custom_filter, :apply_custom_filters, :new_filter, :public_valid_options, :remove_custom_filter, :remove_muted_tags, :results_filter_callbacks, :results_filter_callbacks=, :tracked_filter, :unread_filter, :valid_options, :validate?, :validators, :yaml_tag]