^Well, the tech staff of the modern Trek shows were well aware that writers would make ships go at the "speed of plot," and so in both the behind-the-scenes and trade-paperback versions of the TNG Technical Manual
, they clearly stated that the relationship of warp factor to actual effective velocity was variable depending on local spatial conditions -- that warp factor was a measure of power usage rather than speed, and that in some parts of space you could achieve greater speeds with the same amount of power. And yet for some reason a whole generation of Trek-tech fans ignored that clear statement and assumed that the relationship of warp factor to velocity was absolute and immutable -- even though it never
actually corresponded to any onscreen evidence. Ships onscreen have always gone much faster than the published warp formulae indicated.