Thanks for the reply.
I'd imagine (expect) that Kaspersky would have one database to ensure a comprehensive data source, so "Premium support" would be no better off than regular "Customer support".
The "World class experts" as per the Kaspersky claim must be on holidays.
If there's a fix for a problem, everyone there should have access to it, although they don't seem to have one for the issue I and numerous others have, hence my desire to go back a few years and hope their software doesn't have the same bug.
As for KIS 2019, current products like Premium do not use activation codes, so I'd have to confirm they'd work with current activation methods.