Molasses in a RIS

I’m considering adding 3 lbs of molasses to a 5 gallon batch (24 lb grain bill). I’ve never used molasses before and was wondering if this might be a bit over the top (12.5% of the grainbill). I like molasses flavor and licorice too, but don’t know what to expect. Hoping to wind up with something akin to a Bell’s Expedition Stout. S.G. is estimated to come in around 1.117 by my Beersmith software. Also using WLP 028 since it seemed to be a malt forward yeast strain.

Advice, anyone?