Often times I need to mention some information from the task itself when I'm editing or commenting on it. We can mention users and tasks, but my suggestion is to be able to "mention" values from the project or task, specially the custom fields values.
We have templates for social media posts and they have several custom fields for things like where the post must be published and how much money should be put to promote it. Some of this information like the task title and the other ones I've mentioned are often repeated in the task description or comments. I know this may sound redundant, but often times the information are used/repeated in a context, inside phrases and explanations. Would be great to be able to use them as "variables" and when their values are changed in the custom fields, they are always current in places we want them to be like that.