I have wondered myself, how I would do if applied again right now to a top 5 econ department. In all likelihood the following would happen in decreasing order.
1. They don't accept me because essentially my potential has been revealed. I'm a decent researcher in my field but I'm not winning a nobel prize, and two Ph.D's in econ would be weird. But they have a good laugh about it.
2. They accept me, but I don't pass prelims. It's been 15 years since I took real analysis. That will not help. I have two settle for a weird double masters in econ.
3. I get in, but my spouse divorces me due to the stress of the huge drop in income and uncertainty over the future. I end up playing guitar in a low level country band about how my life went sour.
In short, I don't know that getting additional training matters. All universities care about is your publication and knowledge. Once you've been out a few years, that gets revealed. If I was to cool back to school at this point, it would probably be to get a law degree. 5 years is a lot of time that you could have spent writing more or better papers, and instead you'll be toiling in classes you've largely already learned which are often not relevant for your line of research specialization.