AVR-ISP-MKII with < 3.1V Target?

[w9a9r9p]

The manual says: "Supports target voltages from 1.8V to 5.5V".

The MCU operates at 5V.

I can see how the target data and clock input pins are protected from 5V inputs with a 2/3 voltage divider - down to a target voltage of about 3.1V.
The target voltage on the target connector need only be applied for the reset pullup.

I can see how a data/MISO signal can be received from the target when the target voltage is at least 3V (0.6 x 5V).

But how to program a target with a voltage less than 3.1V?
Should the MCU be made to operate at 3.3V? That would allow a target voltage of between about 2V and 3.7V?

Have I understood this correctly or did I overlook something?

Thanks.