At least for me Vboot does not seem to help when booting completely cold, had it up to 1.45V. But if it fails it is only a little inconvenient to take a quick detour through the BIOS.
Following Rajas advice I did a small memtest session, seems fine:
53.3 also seems to be the optimum for my 8GB b-die 1DPC config.
I then tried to fine tune SoC voltage a bit and found a rather distinctive instability when it was too low (for me that was at 0.95V for the 3200 memory): no code 8 but just a soft reset like behaviour. Might be useful to determine the cause of an instability.