So when we release a new age you want all Beta accounts to be advanced to end tech? Not sure that's a reasonable expectation, even for a test server.
No, Durnasund would become the BA world, where all beta players started at Stone Age and progressed from the starting point of the game up. All beta accounts remain here as they are.
Inno could open a new beta world ...
- and instead of new players in that world start at Stone Age with basically zero coins / supplies, a couple of huts and a hunter, and 16 expansions,
- they start at the last era just before the newest one, with a predetermined number of resources (coins, supplies, medals), a couple of houses, production buildings, Research Tree progression up to just before new Era to be tested, etc..
The new world would be the Virtual Future world, where all players would start at the end of the OF with same amount of resources, space, diamonds, etc. All players would start with the same "basic OF city" equipped with houses, production buildings, cultural buildings, one military building, and roads. Their stock will have a basic set of goods enough to send the submarine to seek for the special good and good of previous eras to be able to start producing OF goods.