For example if you are selling software such as fonts, customers may only want to purchase 2 different font styles/weights. Therefor this would need to deliver different files based on the software which the customer has chosen to purchase.
Light Sans Serif - $20, Regular Sans Serif - $20, Full family of 5 font styles - $80 etc... Each with individual files assigned to their options.
If this could be implemented with the current product options with different prices listed for each item then I think this could be really powerful for stores that sell itemised/customisable software.
I can see this not being explicit to fonts either, this could provide a lot of potential to creators of digital goods, or even a way of billing for services too. Imagine the impact of integrating something like this with Zapier where teams can have certain 'variable' services purchased online by customers, and then using that data to inform other integrations.
Side note - imagine using this with custom option fields for e-commerce items, much like how the CMS allows for custom fields. This would alleviate a lot of problems for vendors who sell bespoke items that may need different prices per material/height etc... Or if you're a digital seller who wants to charge more for customers using their goods in public under a commercial license (instead of a personal one)... just some more thoughts!