With a more advanced AI system, one that could build better physics simulation environments, write software that's near maximally efficient, design better atomic modelling and tools than currently exist, and put all of that into thinking through a plan to achieve the technology (effectively experimenting inside its own head), I could maybe see it being possible for it to make it without needing the physical lab work. That level of cognitive achievement is what I think is infeasible that OpenAI could possibly have internally right now, for several reasons. Mainly that it's extremely far ahead of everything else to the point that I think they'd need recursive self-improvement to have gotten there, and I know for a fact there are many people at OpenAI who would rebel before letting a recursively self-improving AI get to that point. And two, if they lucked into something that capable accidentally by some freak accident, they wouldn't be able to keep it quiet for a few days, let alone a few weeks.
Basically, I don't think "a single technological advancement that product wants to implement and safety thinks is insane" is a good candidate for what caused the split, because there aren't that many such single technological advancements I can think of and all of them would require greater intelligence than I think is possible for OpenAI to have in an AI right now, even in their highest quality internal prototype.
It couldn't do any of that because it would cost money. The AGI wouldn't have money to do that because it doesn't have a job. It would need to get one to live, just like humans do, and then it wouldn't have time to take over the world, just like humans don't.
An artificial human-like superintelligence is incapable of being superhuman because it is constrained in all the same ways humans are and that isn't "they can't think fast enough".