Add one more type of product classes: dropdown date picker
Presently the framework allow to create class as 1/text are 2/field or 3/click check yes/no.
What would be the plausibility for you with your next update to add 4th one that would be dropdown date picker.
This would be very beneficial for the US market, the customers here prefer to select what date they would like to receive their shipping.
This has noting to do with the actual shipping method is option provided and very popular for extra pampering the customer to allow them to select when exactly they would like to get their shipping received.
The selected data should be pass the same way as currently the other 3 product class do record as information in side the order.