As per discussion with @tbradbury:
That's not the way I had been thinking of because it'd only fix it for taxonomy term reference fields and could still be a problem for others (maybe some other entity reference fields).
The label module is trying to display values for any fields that are attribute fields according to commerce cart, and that module allows any field to be an attribute if it has a hook_options_list implementation. So I think to solve the problem for any field that could be an attribute field we'd have to use the options similar to how the cart module does.
I could see if I can write a patch with my idea on the weekend to see if it's actually an idea that would work or not, but I don't think I'd be able to do it during the week due to project work.
Pull request is updated https://github.com/AcroMedia/commerce_pos/pull/12