let's combine those two. the initial radicals are not proposed to be in equilibrium. And actually, looking back at your first answer, it's closer than I initially thought. I missed your equilibrium arrow between the oxetane and the zwitterion. That is not proposed to be in equilibrium, but it's closer to the answer than your seccond answer. The regiodifferentiating step is proposed to be the oxetane fragmentation step, also not proposed to be in equilibrium. The very first, probably very fast, step is association of oxetane and lewis acid, as you have in your first answer.