Actually Troy, you are correct. Respondus does do some things very well. And I know exactly what you are talking about, using Respondus to bring quizzes over to Canvas.
But, I wonder about what you have said. I thought that Respondus somehow connects to the textbook's question bank, and that Blackboard is really not involved. It seemed to me that Respondus was only beneficial if the textbook publisher had an arrangement with Respondus.
Remember that if you could get to the source of the questions, and if they really are in a Blackboard format, then you should be able to get them into Moodle. So continue to look for a Blackboard format for the questions. Have you checked with any of the textbook publishers for any of these 40 courses?
In my own case, I teach 4 courses and use 4 textbooks. In every case, the publisher provides the question banks. For one textbook, I can get the chapter questions in Moodle, Canvas, D2L, Blackboard, and even Angel formats! And even MS Word. For one or two textbooks, the publisher supplies at least Blackboard formats of these questions. Sometimes it's a little tricky using the Blackboard formats, maybe because of the variety of Blackboard products. But I have always had success. One more thing... when Moodle imports most Blackboard formats, pictures come along with the questions!
So maybe you are looking at the wrong way, meaning a Canvas to Moodle. Maybe you should be looking at Textbook Publisher to Moodle? Out of the 40 courses, maybe at least half of these will have their question banks in an import format. And don't forget about MS Word formatted questions. Moodle can import these, but it is often a little trickier.