Currently it is not possible to configure hashtags to trigger a mention.
Example: if "#release" is configured as a word that triggers mentions using this hashtag in a message doesn't trigger a notification. if "release" is configured as trigger, both "release" and "#release" in a message trigger a notification.

(our current workaround for notification purposes is to only use words in hashtags that are usually not used in messages - which can lead to unwanted notifications)