Yes it will go on the G2, but there is good bit of difference between the thickness of the Encore and the G2. If you do not put spacers in to fill the voids I suspect you will have erratic performance especially from heavy recoilers due to the grip/stock twisting under recoil. Also if its not sitting centered and flat in the inletted area may pop one of the ears off.
There is one who makes and sells the grip chip, but its simple to make your own.