@ carpeperdiem: Personal comment on this
I have this for a long time now but not the QT mod - I coded this myself into my stores to correct places where the code belongs. There is no feed to submit - SE will find the tags and it's up to them to index it or not. I don't think this feature is aimed at better sells or conversion - it is to make it easier for customers to see product info in search results as well as ratings instead of going to merchant page... so easy to compare search result right there on that same page.
This doesn't affect site performance - it is simple info included in the html source - it is already available on the product page in XC anyway.
There is no quarantee that SE will display these tags or on which products will display them. This is up to SE to decide. As long as you have them and they are properly formatted - SE will index them at some point.
I have installed this mod on couple carts, I have coded my own on others... both ways work and both ways end up showing the info needed in proper format. I don't think you will make a mistake buying the mod - it will do what it's supposed to do I think. As for licensing and other techinical info - not my place to answer that
