Why does it require so many exchanges with you to get you to explain it completely?
You still have not made it clear how this works. Why would Stewart do that if he gets nothing? Why is Stewart involved?
Why would John burn GEC in order to give someone his fiat?
0. Apparently, I don't think like you do. (See the diagram above.)
Because you assume readers can read your mind. You have massive holes in your explanation which is information that you have already in your mind but you haven't explained to us.
1-2. To carry that USD transaction in the USD economy over to the GEC economy.
This my last attempt. If you fail again to make a long and detailed explanation, then your laziness will be rewarded with an ignore from me.
You still have not explained what Stewart's individual economic motivation is. And why is he involved. Nor have you explained why John has an individual economic motivation to burn GEC when he spends fiat. Nor have you adequately explained why they benefitted from involving GEC in the first place. Seems to me that GEC was never involved. Jane paid John in fiat. John spends the fiat. GEC has no involvement except for some fantasy conjured in your mind.