Yes, this would complement your checker patch from last summer.  It would solve the issue of how to tell or help people, especially beginners, install packages to run with the checker.

Idea for the package manager: include an option to duplicate a set of installed packages from one version to another. A recent SO question (paraphrased): "Started with 2.7, installed multiple packages, added 3.4, can't use packages.  HOW???"  Current answer, with easily missed details, something like: "Packages must be installed for each version.  Use PIP to make requirements.txt (sp?) package list from 2.7 and use that to install same to 3.4."  Nicer answer: use option that gets details right.  Perhaps list could be checked for availability in 3.4.  Or displayed in text widget to be edited.

I look forward to your proposal.