Rule out irrelevant data and calculations when not moving?

[ckcrs]

Hi a good plugin, I'm still figuring this out, thanks.
On server log:
Delta is missing value in {"path":"performance.boatSpeedDamped"} from source "signalk-polar-performance-plugin"
a belive when stationary boat ,i.e. Boat Speed is zero , value still being tried to calculated?
Is not better to rule out irrelevant data and calculations when not moving ,I guess?