As promised, here’s a video on running GRBL-Panel with a Shapeoko 3 XXL (or any S3, really).
It’s quite long winded, I do love the sound of my own voice: https://youtu.be/kGbxkIHce9U
grbl panel can be downloaded here: https://github.com/gerritv/Grbl-Panel/releases/tag/V184.108.40.206
It’s quite a rough take with quite a bit assumed and glossed over, let me know if you’ve got questions. I hope this helps somebody!