I /still/ think a German keyboard ought to have certain extra keys with umlauts on them!
I think that a US keyboard and UK keyboard should have separate keys for stroke of i and the dot above, and for the stroke of j and the dot above.
Anglo-American users are accustomed to a writing system that does not define 'dotting' as part and parcel of the letterform.
German is rich in vowels, as are other Germanic languages including Danish, Icelandic, Færoese, Norwegian and Swedish. The 'dotting' is there because the 'dotted letters' are not letters plus dots, but letters in their own right. Input methods should not be monolingual with modifications for multilinguals. Rather, input methods should be multilingual from the ground up so multilinguals do not have to struggle. The EU is officially multilingual, the US is unofficially monolingual (i.e. there is no official language at Federal level in the US while in the EU there are official writing systems and private citizens as much as Members of the European Parliament are entitled, and encouraged, to use their official writing systems and official languages).
/hh