Можно ли заблокировать темы для владельцев в категории?

[JammyDodger]

Вы имеете в виду что-то вроде плагина Restricted Replies?

Discourse Restricted Replies

Summary Discourse Restricted Replies adds a per-category setting allowing staff to restrict replies on topics to the topic creator and members of specific groups. Repository Link https://github.com/discourse/discourse-restricted-replies Install Guide How to install plugins in Discourse Features This plugin adds a per-category setting allowing staff to restrict replies to the OP, and members of specific groups. This is a bolt-on t…