Function compute_scale 

pub fn compute_scale(accessible_pages: u32) -> u8

Category-#2 memory-access-latency footprint multiplier (×1..4), chosen from the Instance’s total accessible 4 KiB page count. Tiers from ~/docs/memory-gas.md (mem_seq / mem_rand benchmarks). The multiplier is static (resolved once at compile time) and folded into each block’s #1 cost, so it has zero runtime metering cost.