On Fri, 29 Dec 2017 16:29:29 -0600, Char Jackson wrote:

I knew only an expert could answer it as it requires knowledge of Windows
networking that I don't have.

I think you mean knowledge of Opera.

The main intent of the question was to figure out a way to tell, in
Windows, whether there is any practical difference between these two steps,
which are intended to clear both the sequential opera-created "subscriber
id" and the unique SurfEasy created "device_id".

opera://settings/startup
a. opera://settings/clearBrowserData (with "Enable VPN" checked)
b. opera://settings/clearBrowserData (with "Enable VPN" not checked)

Whe
Device-ID (generated upon VPN connection by SurfEasy Inc)
Cleared by Opera: Menu More tools - Clear browsing data
[+]Third party services data
Subscriber-ID (sequential connection to Opera Inc)
Cleared by Opera: Menu More tools - Clear browsing data
[+]Browsing history
[+]Cached images and files