Do you need to change it? No, you can leave it at -29 it's only one off, each value is 3-6mV. Just saying it will likely work at the max value of -30.
Check your Ryzen Master settings, it should default to write CO and PBO changes to BIOS. You can disable that if you just want to use Ryzen Master to test drive your changes. That way if it's unstable just reset/reboot and it's back to normal.
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT