Im only seeing the raven dag consuming about 2500mb on my miners, so I think these cheapo 4gb 470s are good until something like the end of 2021.  I really hope to see more cryptos adopt the KawPow algo, it seems promising as far as keeping the asics at bay.  Last I heard Zcoin is looking into making a switch in future from Mtp since that algo adds a lot of useless data to the blockchain bloating it.