Hey Solgae,
I did test the 2.10 version in an earlier release and it did indeed fix the issue with Chrome extensions.
I did found out that you can manually install the addons if needed, procedure is quite interesting though .
You need to go to this URL Start | Chrome Extension Downloader, copy the URL extension you want to download into this page, download the .crx file, unpack it and them remove the underscore in front of the Metaframe folder. Than you can import the extension using developer mode and the load unpacked extension option in Chrome.
We also removed the updated for Google Chrome entirely (in our case in the golden image but i guess it will be the same for Appstack) by removing the Google update task in task scheduler, removing both update services and removing the update folder in the Program files directory of Chrome. If you then go to Help --> About Google it wil give you an error that it can't check for updates. This way you control which version users actually get.
To this day it seems to work quite well..