Constant forest_filecoin::eth::SAFE_EPOCH_DELAY

pub const SAFE_EPOCH_DELAY: i64 = 30;

From Lotus:

Research into Filecoin chain behavior suggests that probabilistic finality generally approaches the intended stability guarantee at, or near, 30 epochs. Although a strictly “finalized” safe recommendation remains 900 epochs. See https://github.com/filecoin-project/FIPs/blob/master/FRCs/frc-0089.md