The ASRock B550 Taichi showed good headroom for overclocking. I was able to achieve 4.44 GHz at 1.35 V core voltage. The nature of Ryzen 3000 processors has not changed since X570 launched, so I would not recommend manual CPU overclocks for most applications.
For the B550 launch, I am also conducting a memory timing test. This is a pass/fail test where I load the DRAM Calculator "fast" preset for my Trident Z Neo kit (Samsung B-die). A board receives a pass if it can run through three loops of MemTest64 with no errors. Partial credit will be given to a board that can get into Windows, but fails MemTest64. As validated by my MSI X570 ACE motherboard, this CPU and memory combination with exactly these sticks can run without errors at these settings.
The ASRock B550 Taichi was only able to reach 3666 MHz stable at XMP timings and voltages on my Trident Z Neo kit.
For the timings test, the ASRock B550 Taichi was not able to boot into Windows. While no B550 boards have yet passed this timings test, this is not a great result overall.