Binding with indexed properties

I have been working with binding towards a model that use indexed properties (using string identifiers), and have some issues I can't seem to get around - I was hoping someone here have some answers, or could point me in the right direction:

1. The binding does not seem to accept identifiers with punctuation in it - however this is a perfectly valid identifier (this notation works fine using WPF). The binding in Xamarin.Forms seems to parse the identifier as if it were a property name

var binding = new Binding("Item[order.id]", BindingMode.TwoWay);

1. Binding to indexed properties does not seem to update when the source updates (the source triggers a property changed event with the property name set to string.Empty). Again; this works fine using WPF. I have also tried sending a property changed event with other variants (like "[]", "[order]", "order"). Is this not supported?