>a boxed licence upgrade for perpetual licence holders
Is this the "upgrade now" button under "Enterprise Maintenance Extension" option on the "buy" page?..

VVG wrote:where is info about ($) upgrade from v4 regular?

+1 here.
The promo email says: "[...] and also as a boxed licence upgrade for perpetual licence holders."
Where the info on that? No downloads for regular license holders.

This is a MESS. links to downloads don't work or link to version numbers that don't make sense- linking unity accounts is a mess., some versions are called VR some are called studio, some are called standalone and yet download enterprise versions.
+1
Plugins need to be sorted out too. E.g. poser ...