Edge Color by Axis is indeed coarse and quite useless as a means of verifying absolute accuracy.
As shown, the Text Tool displays endpoint coordinates by default.
Text tool is useful but rather slow and cumbersome for this, plus there’s the clutter of text it creates.
Query Tool is what we need here. With this you can quickly interrogate the model.
Utilities Tools includes the Query Tool — Extension Warehouse
Attempting to fix a wonky model will in some ways help you learn about manipulating geometry.
You’ll also learn to judge when it’s best to scrap it and start over.
It’s a simple object one can model accurately in a few minutes, why waste more of your time?
Tips:
• Model the box with square corners from which to easily pull guides for hole layout. The radiused corners last.
• Turn off length snapping
• Set precision to 0.000 or more
• Make a habit of always using inference locking and keyboard entry of dimensions.
Don’t click and hope. Tell SU exactly what you want with inference locking and keyboard entry.