Constant CONSOLIDATION_CREDIT_PER_UPDATE 

const CONSOLIDATION_CREDIT_PER_UPDATE: usize = 8;

Fuel each inserted update credits for policy-requested effort, scaled by the spine’s effort multiplier, which is 1 unless set with with_effort. A granted request spends the effort the policy returns, so credit funds one grant per effort / 8 inserted updates, about 125 at the cluster policy’s effort of 1000. Small batches fund no grant from credit, and the banked allowances per batch are what bound them. The multiple matches the least introduce_batch already funds per update for active merges, which is 8 << level.

NOTE: the credit bounds how many requests are granted, not the work each grant causes. A grant with no merge in progress introduces a virtual batch, which can start a merge up into the largest layer, and that merge then finishes unfunded. See the module documentation of funded_spine.