Index Coop cannot do it:
"Hey guys, FYI this product launch has been pushed back indefinitely. The Synthetix Debt Pool is now long ETH with ETH being introduced as an asset, stakers can use to mint synths. Thus, the SMI would need an ETH short product to be able to hedge effectively. That is not possible today.
IIP-25: Synthetix Debt Pool Mirror Index
IIP: 25 Title: Synthetix Debt Mirror Index ($SMI) Status: Proposed Author: David Goldberg and Andrew Trudel, Synthetix, overanalyser (@overanalyser), INDEXcoop Created: 30th March 2021 Simple Summary When staking Synthetix, the user takes on a share of the synthetic debt pool. This is comprised of all the circulating synths at their relative market capitalisations.