Hello there, @dtavernier ...
There are two possibilities for you when adding additional columns of ratings to your rubric(s). First, you can check out the section on "Add Ratings" within this Guide: How do I add a rubric in a course? - Canvas Community. The other option is by using a handy work-around developed by @James Jones where you first build your entire rubric within an Excel spreadsheet and then copy it into Canvas where it builds out the entire rubric for you. I've used it countless times, and it's saved me so much time creating rubrics for our courses. It's a "Canvancement" (Canvas Enhancement), and so it's not part of the "core" Canvas product, but it's quite awesome! Check out Importing Rubrics from a Spreadsheet - Canvas Community for more information.
I hope this will be of some help to you. Sing out if you have any other questions about this...thanks! Take care, stay safe, and be well.
