Honestly, I kinda thought that this is what the d4 pool would turn into. I don't love the crv3pool monopolizing the stablecoin markets or its reliance on USDT. I don't think a USDT implosion is imminent or anything, but it is a centralized, sketch USD coin that isn't based on US soil. Lack of control makes USDT a much more likely target for the US government than USDC.
3pool needs to be challenged for liquidity depth for many reasons.
Frax minting directly into the pool could be an issue if not used responsibly (or if malicious control over the minter is gained). To be fair, that applies to malicious control of just about any of the d3 contracts.
Incentivizing deep stable liquidity that isn't linked to USDT is pretty much a public service to the DeFi community at large. I've already beat the drum about partnerships enough so I won't do so here.
I'm sure you're expecting this question Scoop, but what happened to Liquity in this equation? Conspicuously absent.
Regardless, I'd be in support of the proposal for similar reasons to the d4 pool previously.