Imperial Units / Feet, Inches, Lbs, etc

My customer is in the US. Is there a way to have Imperial units for dimensions and weight?

Yes. You can name them in the backend under settings > measures (I guess it is named that way).

Won’t that affect shipping calculations if I just relabel the units?

It is just a label (text).

2 x 2 = 4, does not matter if you use cm or inch.

What about the Measures & packaging section of the Product Specifications tab, in Administration? I’ve been trying to get my twig overrides (sw-product-packaging-form block in sw-product-packaging-form.html.twig) for that to work via custom plugin, but it doesn’t seem to work.

Do I need to run bin/ to get my plugin’s overrides to take effect?

Yes, you do. Your JavaScript needs to be compiled.