Reuse a cpo option or field slug

Hi!

If i duplicate a product then it is working, but if i create a new one and i would like to use it again without changing and saving it to DB, then the price calculation will return with zero.
For example:
i have a uni_cpo_width_mm (width in milimeters) and i copy the whole product then it is working, but i a create the product it is not working.
I do not want to create new uni_cpo_width_mm_2 and uni_cpo_width_mm_3 and etc, and use a lot of cpo option which slow the db later. If i have a width in milimeters i would like to reuse it. I will use a lot of other cpo option too for example uni_cpo_width_meter, uni_cpo_width_cm and etc.
Why is it working only with duplicate?

Thanks!