For informational purposes - the DevRel team has tested the code that generates the call data in Chopsticks and it is all good.
Ideally with the introduction of RT3700 - we can test the full flow of swapping GLMR for USDC and then transferring it back and doing a Treasury spending in stables, to confirm the entire flow.
On another note, the furrent flow will leave the USDC in the Moonbeam Sovereign account that is in Hydration. We will need another governance proposal to move it back to the treasury account in Moonbeam (via XCM).
Also, I just thought about this proposal. The treasury has also 500k GLMR in Hydration