OK… in my slumber I’ve missed something… my ShapeOko1 has a grbl shield, what’s TinyG?
Another motor controller.
https://www.synthetos.com/project/tinyg/ a motor controller with very good motion control algorithms. It accelerates and decelerates much more smoothly than standard grbl resulting in faster and more accurate moves. I believe if you can now run the firmware on an Arduino Due though so that might be an easy upgrade path.