Language during shipping computation method?

is there a way to get the localized string from the shipping computation method?

The FixedByWeightByTotal will do it:

...
Name = _localizationService.GetLocalized(shippingMethod, x => x.Name),
Description = _localizationService.GetLocalized(shippingMethod, x => x.Description),

But other providers (e.g. UPS, FedEx, etc. don't).
What provider plugin are you using?

My own i was wondering how i access the localized strings my plugin creates from inside the computation method

As per the above code.
(does that help, or do you still have questions?)