When I worked in military avionics, we used a MIL-STD-1553 data bus to communicate between Remote Terminals. The Bus Controller had a transaction table that determined the order in which it talked to the Remote Terminals. This sequence was fixed except for a few "random" messages that could be inserted.
If your test setup sent out I2C messages in a similar known sequence, then you could in theory configure your I2C slave device to switch to the next address in the sequence after each message. Store the address sequence on the slave and you would not need any additional I2C messages.
Perhaps the I2C general call message could be used to reset the sequence.