Measurement Accuracy Issues with Intel RealSense D435 in Box Dimensioning

I am using the Intel RealSense D435 camera along with the Intel RealSense Viewer application to measure some boxes. I use the measurement function in the RealSense Viewer to determine the dimensions of the boxes. The boxes have dimensions of 60 x 40 x 10 cm. The camera is placed approximately 60 cm away from the box, which is positioned on a white table.

Each box also has a hole with a length of 10 cm and a height of 6 cm. When measuring the holes using the Intel RealSense Viewer, I get fairly accurate results. However, when measuring larger dimensions such as the length of the box, the measurement error increases. The error becomes even more significant when measuring the height of the box.

For example, when I measure the width of the box, I have an error of 1 mm but when i measure the height of the box, I get an error of 1.41 cm.

My questions are:

Is this camera accurate enough in this setup to achieve measurements within a 5 mm error range?

Are there other Intel RealSense cameras better suited for this task?

How can I calculate the expected measurement error and improve the setup?

Why the error when measuring the width is much less than when measuring the height when the camera is looking directly at an angle of 90 degrees to the box?