Allow Product Add-Ons to add/chain extra options
I have a client who wishes to have a general accessories cross-sell option on their product pages. Whilst Mike Jolley's great Product Add-ons plugin meets most of this requirement, it's not currently possible to add ('chain') product add-ons.
So for instance if the user selects a Product from a Select box, it'd be great for the plugin to then add another Select box underneath (admin would specify what type of option group would be inserted). I know you can offer checkbox options for categories, but this isn't ideal for large add-on sections...
Providing this function would be beneficial in that it can boost sales without overwhelming the customer with a large amount of checkboxes/fields/sections before they even see the add to cart button!
Another feature that'd make this even more powerful is customizing the dynamic inserted field based on the user's selection, enabling sub add-on products.
For a very basic example of what I mean: http://jsfiddle.net/h4TGV/