What stock pattern? Do you have it in hand,or on order? Is the Seven something you already have?
If all of it is in hand and you are good to notch the underside receiver ring(feedramp),then the binderless AICS mag will grant some nice COAL increase.
I may,or may not do it,depending upon stock pattern and certainly wouldn't use the typically supplied pillars,as their great O.D. will compromise integrity. The key to procuring PT&G wares,is to NEVER buy direct...go through Midway or similar to purchase.
I'd take a step back,cypher what you are trying/hoping to do and objectively quantify everything............................
I notched a CM 700 SA for shooting 7-08 162 smooches through a 1-9 NSS with a dremel. It was pretty easy, I would do it again. I do wonder how much harder a SS action would be to notch. I’d like to build a little lighter all SS 7-08 that could squirt 180s.