backbone87/contao-core — comment on commit d71ed755fcd6e35cb0509caf5cb0a87fa9d47dd7
File:  line 0
By backbone87:

Subdomains are not that corner case feature of the web... The reason why it is not needed by more users, is because there are no extensions, which utilises this feature, and the reason for that is... the feature is missing. The duplicate content problem is caused by missuse of this feature, you can achieve the same problems by messing around with include CEs.

There is no way to overwrite the getRootPageFromUrl-method. And there is no way to replace the setCookie method, too. And the getPageDetails method, too. I would like a hint how to integrate it flawlessly as an extension. I have thought about it, and no way has come to my mind.