TechPowerUp checked out the ASRock B450 Gaming-ITX/ac
A quote from the article:
ASRock has applied the Fatal1ty treatment to AMD's B450 chipset, and in a way that only ASRock can; using the Mini-ITX format. It's not often that we get such a truly gaming-oriented mITX product, that can also handle some overclocking, and supports 3466 MHz memory speeds.ASRock B450 Gaming-ITX/ac Review