As I understand it, chelation can pull out a lot good minerals as well. Some doctors that do chelation give lots of mineral replacement to try compensate for that.
However, it does not seem likely that you could stay in balance with that approach. i.e. Can you supplement (and absorb) minerals in the same ratio as they are being stripped out with chelation. Especially the "non major" minerals that might not even be in the mineral replacement.
I guess that is why Eck / Wilson preferred the slower route.
My magnesium has generally been within range the last couple of years, or just a little low on one test.