As said in previous posts there not much to change to get 2017.2.0621 to get working:-
In class DataSourceRequestModelBinder function public virtual Task BindModelAsync(ModelBindingContext bindingContext) change the return to Task.CompletedTask
in the same class function TryGetValue replace action((T)value.ConvertTo(typeof(T)));
with :-
object valueToConvert = null;
if (value.Values.Count == 1)
{
valueToConvert = value.Values[0];
}
else if (value.Values.Count > 1)
{
valueToConvert = value.Values.ToArray();
}
var convert = TypeDescriptor.GetConverter(typeof(T));
action((T)convert.ConvertTo(valueToConvert, typeof(T)));
worked for me and am using it in production - I may have missed something but didn't find it too hard.