The power supplies used in today's systems are not Auto-sensing and that leads to a lot of the confusion with questions like this. The power supplies are wide ranging. May seem subtle but it is a huge difference in how the power supplies would behave. As far as the power supplies in a redundant system they are fully isoltaed from each other. PS1 has no idea whether PS2 is running at 100V or 240V. Just think if you had two independant sources feeding your supplies; one from a UPS and one from a generator. The input voltages may be different as well as the input frequencies. The PSUs have to behave based on their own input.
As long as the system in question has no issue with "losing" one power supply as you remove power from 120V and then reapply with 208V then what is being proposed has no technical issuie. I am very familar with servers but no as familar with storage, so please double check how the device behaves at a system level. Again from a hardware/electrical level there is no issue.
Notes: Auto-switching means there is some fundamental change in operating behavior between one setting and another such as a set of relay contacts being changed. Our supplies do not do this. Wide ranging means the device can opearte across a wide range of input voltages and meet all of its published specifications. Our supplies operate from 100-240Vac (rated) input voltages. Any input voltage within this range is acceptable.