I am converting courses to Canvas and cannot seem to figure out how to make things happen the way that I need them to happen in the discussion. My sense it that it will require substantial workarounds for tasks like grading (things that take 2 clicks in Blackboard), but perhaps someone else has figured this out already.

My classes (to help explain what I'm trying to do): I teach online graduate level classes. They are highly interactive. In a typical week, I propose 4-7 discussion topics (each as a thread in the forum), and my students will often add a few more of their own. They do not have to answer each of my prompts, which are merely discussion starters, nor do they have to participate in each thread. I encourage my adult learners to self-regulate and participate in the discussion in the ways that are most meaningful and relevant to their own learning processes. I have minimum discussion posting requirements, but my students tend to far exceed these requirements. Our robust learning discussions may get threaded 10 levels deep at points, with students changing the message subject lines to provide meaningful cues to the direction the discussion is taking. I grade my students via the Blackboard grading tool, which allows me to see all of a student's contributions for the week at a glance.

I understand that forums are not possible in Canvas, that each thread must become its own separate discussion. This makes grading overall participation in a given week a potentially cumbersome process (I do not want to engage in point-per-post grading and my students are not required to participate in each topic). I also understand that we cannot modify the subject lines within a discussion. It appears to me that the Canvas discussion tool is really designed for courses that use discussion tools to support instructor-centered message posting (e.g., all students must write a mini-essay in response to my discussion question) over truly discursive, social constructivist learning experiences such as one would expect in a graduate-level seminar. I feel like I'm trying to do something the tool just isn't set up to do.

The only workarounds to achieve my goals that I can see right now involve:

• Give up altogether on the ability to have subject lines changed to reflect the direction the discussion is taking
• Set up a discussion for each topic I would like to propose each week, using titles like "Week 1: Exploration of epistemological orientations" and "Week 1: Debunking the learning styles myth" to cue my students to the correct week and give a sense of the topic to be found within.
• Link these discussions in to the weekly module so they can be found easily.
• Set the discussions to be ungraded.
• Give up on having students start their own discussion topics (if not linked in to the weekly module how would they be found by anyone?)
• Create a new assignment with no submission so I have a space to enter the grades for discussion participation. Hide that assignment from the assignment list to avoid student confusion. 
• For grading: Use a spreadsheet (so, do it the old school/offline method) to track participation across the 4-7 topics each week to ensure that each student has participated at the minimum required level and in the manner that meets my basic parameters (across the body of messages for the week, I expect them to be responsive to the readings, responsive to peers, posting across multiple days in a discursive manner, etc.)
• Enter the grades and feedback into the dummy assignment so students can access them.

Beyond this, all I can think of is to seek a third party discussion tool. That said, if anyone has dealt with this issue and solved this problem, I would truly love and appreciate your input! Locally I've just been told that what I want to do cannot be done.