I agree with this, which is why Weaver came so naturally to me. I spent most of my life practicing various fighting disciplines and because of that, a "fighting stance", which Weaver resembles is what my body does instinctively. I have been trying very hard to adapt to Iso, but intrinsic movements are hard to break.
I'm guessing that you are assuming that Iso means having your feet side-by-side, and you are more comfortable having your support foot forward. The fact is, the position of your feet is completely unimportant when shooting Iso. Furthermore, you should practice with your feet in different positions, so that you are comfortable shooting no matter what your foot position is.
You can shoot Iso with your feet side-by-side. You can shoot Iso with your support foot forward. You can shoot Iso with your strong foot forward. You can shoot Iso while kneeling. You can shoot Iso while leaning around a barricade. I've watched a USPSA Grand Master shoot Iso while jumping up and down on one foot.
Put your feet however you like them. Now stretch out your arms in front of you. Now you are in the Iso shooting position. Done.