If you have purchased any version of WM Lab application then you can upgrade(other than Major Release) it to latest version with no cost. If a product is released as Major Release, then you won't be able to upgrade but you can always install a fresh version of the application.
Code canyon offers two different types of license:
Regular License : You can use this license only at one location. You can not even install the application with the same license at another location. Anytime if you want to move your script you can simply release license from existing installation and then install the application again on any other or same location. Release license link is available in the header menu just below the Change Password link & it is only available to the Admin user. The screenshot is as below:
Once you release license, you won't be able to use it in that location & you will be able to install the application at another location.
Extended License : You can use the application at multiple locations by using same purchase license.
Regular license can be used only at one place at a time. So
Also note that anytime if we found that you are misusing the regular license like installation or usage the script two or more place at a time (local or live) all your support will be blocked immediately and your purchase license will be blacklisted.