How do I disable Google Chrome extension autoupdate?
If the chrome extension is on Github (which many if not most of them are), you can simply:
(1.) clone the Github repo,
(2.) reset the head to the version that you want, and
(3.) enable Developer Mode at chrome://extensions/
(4.) select the "Load unpacked" option from chrome://extensions/, and then select the folder enclosing the source code for the extension.
I recently used this technique to downgrade my version of Reddit Link Opener, which no longer supports users who have opted out of using that site's redesign. This worked for me on MacOS, but should work on all platforms.
If the extension is loaded as an unpacked extension (in the manner described above), it will NOT auto-update to a newer version.