Sprint Overdrive Pro w Peplink 30?

We are looking at using a Sprint Overdrive Pro (4g) along with 2 DSL lines for our office until a better option is available sometime next year. Two questions:

  • Will the Overdrive Pro work connected to the USB on the peplink as a means?

  • Does the 4g connection get used only when the 2 DSL’s go down or is it live all the time (we have unlimited data, so we prefer it be used)

Thanks. The background is that I’d rather get the Overdrive Pro that could be more useful once we have a better solution.