Just to clarify: is the problem the physical keyboard oh L14? On both L14 and L5 you can specify German keyboard layout (even if you use English as language). On L5 the terminal keyboards haven’t been yet localized (in hindsight it’s odd to have “normal” and “terminal”) but that can be done, more keys added and modified (see here).
I’m interested in the general subject because I too want to have my native characters available and have trouble due to US layout being used here and there.