The First Run Engine specification adjuster is a value addition to an engine, which should be applied if the engine is on its first run ie, it is yet to have its first performance restoration shop visit. This value add-on takes into account the typical additional time on wing you would expect from a new engine compared to a used one and thus the premium it could command over a used engine.
The additional value for the first run add-on will only apply to the Current Market and Base Values, not Future Values. This is because we cannot predict when the engine will enter its second run and thus, the value add-on it would command for being a new engine would no longer be applicable.
For more information on Values methodology see here..