Is it an early Stance? They had problems with them through early 2015, end of 2015 they made a change to the manufacture of the triangle. A Stance should handle most of what an average ride throws at it. I have a late 2015 Stance, I weigh 200lbs, ride mostly technical trails, have hit things pretty hard, and have never had an issue. Makes me wonder if it was cracked before you bought it and the seller didn’t realize it, or didn’t disclose it.
I have made several measurements, contemplating trying it on mine, and I believe a Anthem triangle and bottom link will fit. Might be worth looking into. For only a little more cost it would upgrade it to a Maestro suspension.