Alpha should vary logarithmically with context length to track the changing optimal operating point
3-bit and 2-bit alpha curves go in OPPOSITE directions. 3-bit: alpha = 1.075 - 0.007*ln(n_kv) — decreases with context because longer context provides more CLT averaging that compensates for quantization shrinkage naturally. 2-bit: alpha = 0.887 + 0.020*ln(n_kv) — INCREASES with context because 2-bit errors are large enough that CLT averaging amplifies systematic bias rather than canceling it. Zero runtime cost — alpha is a single multiply on the V norm during decode, and ln(n_kv) is trivially cheap. Beats fixed alpha by 2-7% KLD at 8K-32K context lengths.