Or will it never know about the editor template due it being server side?
This is correct.
In JS, column.editor has to be a function, so you can't directly use server-side editor templates. The equivalent would be something like this:
columns: [{
field: "fieldName",
editor: function (container, options) {
var input = $('<input name="' + options.field + '" />');
input.appendTo(container);
input.kendoNumericTextBox({
min: 0,
decimals: 0
});
}
}],