Okay, I followed up and verified that if you want to mine on Vegas, you can use 18.3.4 drivers.

That said, I'm not sure what this miner offers that tdx doesn't... on Vega 64's I was getting 7.3 MH/s vs. ~6.3 MH/s or so on this miner. The only extra that this miner offers is the possibility for reduced power consumption in windows via PPT mods.

Maybe that's worth a 20% hashrate reduction; I doubt it though, the numbers I was calculating indicate that it's still more profitable to stay on cryptonight coins. Perhaps that will change if ETH continues to tank and miners start to migrate to CN.