[PlasmaKrab]

+1 point when recalculating looks like rounding error, one way or the other.
I already have seen that when repricing oobs, when units I hadn't changed a chip were calculated with one point more or less.

Probably Don and Andy can tell you more about how the Cost Calculator really proceeds.

Anyway, +-1 can be safely neglected, particularly when your unit is an expensive aircraft.