I think, it would be possible to establish links form the tiddler info area, or the “pink banner” to this forum.
There is a possibility to automatically create new topic with Discourse using URL links. … BUT I don’t know, how this mechanism behaves, if a topic already exists.
See: How to create a new topic link with pre-filled information - faq - Discourse Meta
Someone other than me would need to read the stuff and make some experiments.