LTC3122 - variable output voltage

I would like to use the LTC3122 boost converter in an application where I need a variable voltage level between 5 and 12V.  The input voltage will be between 1.8V and 4.2V.  I was thinking of placing a Maxim MAX5419 digital potentiometer in the R2 position of the feedback network (FB pin to ground).  Do you see any issues with this setup?  I plan to disable the device by pulling SD low during the time when the potentiometer will be adjusted.

Thanks for your help -