Crack the Vault
A window sweeps around the dial. Stop it while your target digit is anywhere inside that window, five digits per level. Three wrong stops, at any point, and the vault re-locks from level one. The window gets narrower every level, by level four there's no margin left at all.
LEVEL 1 / 4
catch this digit
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1
2
3
4
Vault cracked
All four levels down. Nice hands.