The Zip contain PHP code that normally is already updated in your master.
The problem of the Upgrade is the DB table layout and content that can be modified.

I don't think that a tool that compare the files on the disk will also be able to compare the table structure of different website and also read the content of each table to discover what should be added depending on each extension.

So, I am still convinced that this will not work without re-installing the extension in the slave site as you need to call the specific code written by the authors of the extensions.

Ok thanks for that explanation.

I have another 2 minor questions:

Q1: When we have an x icon ('Define from Master') can we manually install the extension into the slave site directly via the slave admin or do we need you to include the definition in JMS?

Q2: Regarding Q1 above, if we can install this directly into the slave via the slave admin are there any additional limitations that we should be aware of?

Thanks and regards.

Q1) When this is for a component, you have to re-install the extension in the slave site and if you want to be able to install it inside the JMS tool, you can to send me the package in the attachement of an email to add its definition in JMS.

If this is a module or a plugin, in most case, you can define it because this suppose that you have a component that had installed the MySQL table required for the module or plugin.

Q2) If you are able to re-install in a slave, this should be OK