Unopened Acrobat Standard 2017 forces us to sign-in and unregister other product

Installed Acrobat Standard 2017 out of the shrinkwrapped box. Used our single Adobe account to try to register it. Despite using the serial, it tells me I'm only allowed to have 2 installations (of previously shrinkwrapped product) at one time. My only option (because who would be signed in to product I just opened the box for?) was to 'unregister' whatever other versions they thought we had.

We are a corporation. We use one account for all things including our CC licensing console. Going forward, we will be doing the CC/DC online licensing.

I understand that I can't unify our existing product going forward to the new licensing management system, but I'm afraid that limitations in the system will prevent us from moving forward with thousands of dollars in Adobe products that we should be able to use and uninstall, unassign and repurpose for years to come.

I did chat with a CS agent. His only suggestion was to register it with an other Adobe ID. we can't manage boxed software registered to individual users.