Currently Zinnia doesn't seem to support allographs. See http://en.wikipedia.org/wiki/Allography for an explanation.
For example the hiragana "ki" can be written like this:
or like this:
The letter "a" can be written like this:
To improve the accuracy, each allograph should be trained separately. The way to handle this is to allow characters to have a name and an output. For example there could be two characters named "ki1" and "ki2" (names must be decided by the person who trains the model) which both ouput "ki". For characters that don't have allographs, the name and the output will be the same.