A single A/B comparison answers what changed last. It cannot tell you whether the model is stabilising, or when a value first started drifting.
How it’s made
Frame walks every consecutive pair in an ACC model’s lineage — all versions, the latest few, or a range you pick — and stitches the comparisons into one semantic model. Nobody else builds this; it is the reason the template exists.
How Frame builds it
Every pair in the lineage, not just the last one
Two things fall out of it. Drill through from the trend into any single step, v2 → v3, and see exactly what moved. And read any parameter as a time series: one row per element, per version, per property, with the value resolved to numeric, boolean, or text alongside its unit. That is how you chart the price of concrete across nine revisions, or find every element whose fire rating was edited after the tender issue.