Looks good and sounds good. Will be interesting how the MPG works. I have never been able to get the MPG work well with the SS nor the ESS. I want it to work in Velocity/Step mode like on commercial controls but it neither as responsive nor the step size is correct.
They don't exactly provide this information in the manual, but based on their Active Low setting in Ports and Pins for the limits (on page 20) I think that the inputs are normally pulled high. Changing it to Active High (uncheck the Active Low box) should fix this.