"MilestoneStatusIcon" is a standard field in Case Model but we are unable to add it to Case Model and thus cannot display the same in the page. Will appreciate any inputs or thoughts regarding the same.
I don't use that functionality, but if you are unable to access the field in Skuid, you may have to rebuild that functionality. You could do this by rendering icons based on milestone status. It would depend on where and how you need those icons to appear, but you could render a check mark if the status is compliant and render a warning icon if the status is open violation.