Currently we can read a parent field in an inner form but we would need the reverse: being able to set a parent field from inner form in on_change method

Currently we can read a parent field in an inner form but we would need the reverse: being able to set a parent field from inner form in on_change method.
We would use a syntax like:
return {'value':{'parent.myfield': str(auxDataFinal)}}
see details here: http://openerp.com/forum/topic12797.html?sid=363d7bb157c38481f3b830c2fd6b4d9a

A typical use case where this would dramatically improve the user user experience is the product configurator module:
"product_variant_configurator", after you set up the dimension values for the product (like Size: M, Color: Red), we need to eventually select the unique variant (product.product) that matches the criteria and explicit the user can continue the configuration wizard.
But because we can't update the parent form, when dealing with variant dimension values, we can't do that and user has to click back in the parent form and look up for a matching variant manually, still there is only one, it will auto-complete. Still that's a good 4 clicks more and awkward workflow...

NB: that would required support from the clients