Delivery Optimization Cache as public CDN
If ISP customers could automatically use the nearest cache node, then ISP can get rid of non-standard caches for saving bandwidth.
I mean "Internet Service Provider" or "Internet Access Provider" for example a company which buys 10Gb of Internet over fiber and then sells it over wireless/dsl/fiber to 1000 customers each one 10Mb .
Actually I think there would be a standard way for ISPs to cache Microsoft updates without need any change in client configs.
For example look at following link https://wiki.squid-cache.org/SquidFaq/WindowsUpdate . It is one of many examples that show ISPs try to reverse engineering the windows updates mechanisms. These ways may create issues for customers/clients.
The main goal is to save bandwidth and I think Microsoft also does not have any problem with that. So please create official way for ISPs to save bandwidth.
Maybe Microsoft think the number of ISPs is low and it does not worth to implement the product for them. But trust me , if there was an official windows update caching product for ISPs without any change in client settings and without any dirty ways like transparent caching proxy, then Microsoft end users may have better user experience.