2 questions about plugin management in LR

OK. Answering question #1 to myself.

The Remove button in the Plugin Manager is only enabled when you have used the Add button to install the plugin when it is stored in another folder than C:\Users\<user>\AppData\Roaming\Adobe\Lightroom\Modules\the_plugin.lrplugin. When you do this, the path to the added plugin is inserted into the AgSdkPluginLoader_installedPluginPaths section of the Preference file and this is where LR looks to enable the Remove button or to leave it disabled. The plugin is not moved to the default folder. If the plugin is installed in (or from) the default folder, the button is not enabled anyway.

If you copy a plugin subfolder directly to C:\Users\<user>\AppData\Roaming\Adobe\Lightroom\Modules, the Remove button is never enabled, even if you manually add the relevant information to the AgSdkPluginLoader_installedPluginPaths section.

I'm wondering why I should not be allwoed to remove a third-party plugin installed in the default folder ?

Anyway, this indirectly gives me an unsatisfactory answer to my second question. Since the only way to remove a third-party plugin installed in the default Modules folder is to merely delete it, this implies that no particular mechanism is triggered allowing the plugin developer to cleanup things during a (non existing) uninstallation process.

Not surprising that Adobe constantly recommends to reset the preference file when something is going wrong. If you regularly install, try and uninstall plugins, after a while, the resulting preference file is probably a mess containing a lot of entries pointing to non-existing plugins. Not clean. Not pro.

So, the only solution in order to keep the preference file more or less clean when installing and uninstalling plugins is to use John R. Ellis Snapshot Prefs.

Thanks John.