In practice, narrow edge-banded parts are cut as an oversized blank and trimmed to size only after edge banding — otherwise a thin strip cannot be clamped and banded neatly.
How this is accounted for in cutting
The cutting calculation can take this technique into account: narrow parts go into the layout with an allowance for subsequent trimming, rather than at their finished size. The feature is enabled at the manufacturer's request — for those who work with this technique; by default, cutting calculates a part at its final size.
Why it matters
If a narrow part is cut straight to its finished size, after edge banding there is nothing to clamp it with and nothing to trim it flush — the edge comes out uneven. The allowance gives a margin of material that is removed by trimming after the edge band is already glued on.
Result
The material calculation and the cutting map match what actually happens on the shop floor: honest consumption, an honest price, and no material "shortage" on narrow parts.
This is a separate technique from part trimming, which removes a thin layer from the edge with a cutter before applying the edge band to get a clean edge. Here, the allowance is built in at the saw beforehand and is removed by trimming only after the narrow part has already been banded.