Hi, we have V2 integration with D2L, and we have Feedback Studio. I know we don't have to worry about V2 with migration (yet) but does Feedback Studio change things? I believe we can turn off Feedback Studio if we need to, we don't actually want instructors to use it!

I apologize, but I am not sure what you mean by "turning off Feedback Studio because you do not want your instructors to use it".  You are using Feedback Studio with the V2 integration.  If you have the LTI 1.1  integration configured so that users can also have access to Feedback Studio along with PeerMark via Content in D2L (not just in Assignments via the V2 integration), and you do not want that to happen, you can always remove this access route for your users.  But perhaps it would be better to have a conversation with your Customer Success Manager for specific questions about a specific workflow you want your instructors to have in your LMS.  They will be able to provide you with more context and make suggestions that are unique to your workflow.