In non-Stylo builds, Devtools Inspector, in the Computed tab shows a box model with the sizing of the currently selected element with size of the element, of the padding, the border, and the margin. Stylo builds show 0 for all these values. Additionally in non-Stylo builds, underneath the box model, the total size of the element is shown. Stylo builds show "undefined x undefined" instead, and this should be changed to match the non-Stylo behavior.
At some point, this was resolved. Computed tab shows expected values now.