As far as I know, VE is supposed to be enabled by default to all users including anons in most Wikipedias, except English and a small number of others where there's no community consensus or issues with typing the alphabet.
Typing doesn't seem to be an issue with the alphabet that is used for Amharic (am) and Tigrinya (ti). I just tested it with the default keyboard layout on Windows 8 and it worked perfectly. But VE is not enabled in Amharic and Tigrinya Wikipedias.
I believe that it should be work there by default.