From the CEX options I have used Poloniex (poloniex.com) in the past to buy XMR. They do not have mandatory KYC (but have optional KYC for higher withdrawal limits) and supports Monero. They have spot pairs for XMR/BTC, XMR/USDT and XMR/USDC which you can trade without KYC. I think that their limit for No-KYC withdrawals is $10,000/day.
On the negative side, Poloniex has been hacked twice, so you shouldn't keep large amounts of crypto in your wallet there unless you plan to trade actively there (but then again that is true of any CEX). And there is always the risk that they may suddenly block your account and request KYC if they decide that your activity is suspicious, although this hasn't happened to me.
Poloniex is very bad exchange to use.
I joined this market in 2017 and actually experienced months with very shady and terrible technical operations of Poloniex. They did not prepare their infrastructures to meet massive new customer flow into their exchange. Their exchange was super laggy and sometimes even could not access. They arbitrarily put their exchange on maintenance mode without prior announcement/ notification to their customers.
When their customers got access to their accounts, after maintenance, if they had active margin orders, mostly those orders were forcefully closed, accounts were liquidated.
Later, Poloniex was acquired by Justin Sun who is not a man I can trust.