I had also been weighing lot of things before I went ahead.Its a slightly risky one for you. But think about the alternatives. You might have to wait a while before the EB3 becomes current.
And since your dates are current with the other one, you might get your GC if the I-140 clears.
I also can understand that if something goes wrong, you wife would not be able to work. But the issue is we are stuck on a security review...not any other review with our education or companies in which case we would have got an RFE.
So my suggestion would be to take the risk and go for an upgrade.
Punjabi,
My 485 also got approved yesterday. Thanks for all the encouragement you guys provided.