You are throwing terms around that I would have to google.

Apparently you are talking about https://en.wikipedia.org/wiki/Software_Guard_Extensions and not the Singapore Exchange.

"Mercury" though ... ??

I'm in the camp that sees e-cash as clearly custodial so there's no argument to be had about sgx fixing anything.

Now if trusted software was running on SGX to manage the mint, you could maybe gain some assurance that the software used for issuance of tokens was not tampered with but that only means that you now have to trust SGX and not the people who run the mint. Certainly better than without a TEE assuming you had doubts about the people running the mint but they keep controlling the BTC so if you don't trust them ... they can still rug-pull you ... or not? If the BTC keys are only in the TEE maybe not? It all depends on how the TEE is being used.

Either way I wouldn't trust it neither as probably TEEs like SEs in hardware wallets run closed source software and I don't trust closed source software. Getting rugged by those who control the TEE isn't better than getting rugged by those who run the mint.