Which Extensions are you using with 4.7 which do not yet state they have a 4.7 release
There are two major hurdles preventing my extensions from working:

a) settings storage has changed. Unlike many extensions, mine remove their settings when uninstalled.

b) cj being removed in 4.7 as a valid JS format. My extensions need (in theory) to work on 4.4 and I don't think that allows CRM.$

In short, I'm not convinced that they can be made to work without splitting the codebase along versions somehow.