Motor Driver, increase output voltage
The short answer here is, probably not like you would like.  Here are some general points as to why not.

First, the boost converter you linked to is a switching supply(so is the motor controller really, but probably this is not the time to discuss that).  Due to this fact, it will have a settling time for a given change in input voltage.  Because it is designed for voltage stability and not response time, this will likely be very slow compared to the motor controller.  Depending on your application (especially if feedback loops are involved) this could quite possibly be a deal breaker.  Also keep in mind that if you are upping the voltage by two, the input current(at say 30 volts) would be twice the output current (at say 60 volts).  So a motor drawing 5 amps max at 60 volts would actually be drawing over 10 amps off your 30 volt supply(over due to converter efficiency).

Another problem is when the voltage drops below the minimum on the boost converter.  Depending on the design, it will either just pass the input or possibly open circuit the output to deliver 0 volts.  If it passes the input, you might be ok here.

There are probably some other things I am not thinking of, but the critiques will come...I just thought this would get the ball rolling for you.

Edit:  I forgot what I started out to say.  The output of the boost will be independent of the input voltage (within the design range of the boost converter input).  You have to set the boost converter up for the output you want.  This seems like the best reason this won't work as you would like.