Minimum phase difference AD8302

We plan to use the AD8302 to measure the phase (few degrees, <5) of signals with different amplitudes in the 250kHz-25MHz range.  We need phase measurements with considerable precision;  ~0.1 deg.  Can we restrict the phase range of the AD8302 to be narrow (say 5-10 deg), but with high precision?  The default slope is 10mV/deg;  a 100-fold increase would be most desirable in order to discriminate the phase differences.

We are currently using a TSSOP-DIP adapter and a breadboard, in conjunction with a ucontroller, to verify if the AD8302 will meet our requirements.  Any suggestions as to how to implement an optimal arrangement will be appreciated.