Maintain different set of extensions in Chrome, on different PCs

You can turn off extension syncing in Chrome.

Go to Settings -> Sign in -> Advanced sync settings, and uncheck Extensions

This is an rather old question, but still something that have been bugging me. So here is my own two cents.

You might be able to use an another extension to do this. I myself have been switching between these two plugins: "Extensions Manager (aka Switcher)"

Handy extensions, applications & themes manager. Light popup manager to enable, disable, uninstall extensions, applications quickly and easy.

or "SimpleExtManager"

A simple menu to enable, disable and access options of extensions. Another addition to the 'Simple' series. This time its an extension manager.

Features include:

• basic function to enable/disable, access options and uninstall extensions via popup
• customize the popup
• ability to create extension groups
• enable/disable extension groups via popup and right-click menu
• event page enabled

I like both of the extensions, but haven't gotten to a point where I can say which one I like the most. Both of them are going through a lot of development and are updated frequently.