When a room needs a custom whiteboard sized between standard options, trimming a larger standard board down to fit can look like a faster, cheaper route than ordering a genuinely custom size. In practice, the two options age very differently once installed, even though the difference is rarely obvious on day one. The apparent savings from trimming can also be smaller than expected once the labour involved in cutting and refinishing an edge on site is properly accounted for, rather than assumed to be a minor extra step. It is worth asking directly what a trimmed edge will actually look and feel like once finished, rather than assuming it will be indistinguishable from a factory edge without seeing an example first. A short conversation with a supplier about how they typically finish a trimmed edge is usually enough to clarify whether it will meet the standard expected for the space.
The core material underneath, an FSC-certified MDF panel with a Cradle to Cradle Bronze certified enamel surface, stays the same either way, so the real difference between the two approaches comes down entirely to how the edge itself is finished.