Are you sure it is the overload that trips, and not the low oil shutoff?
I ask because that possibility is easy to check and cheap to fix (ie, check oil level and add if necessary). And I can see how, if you were right on the line, the tiny momentary rpm increase due to a sudden drop in the load might cause the wiggle in oil level needed to kick you offline.
If it is the overload, not the oil, it suggests an electrical problem that might need the attention of a Honda tech. When a substantial load drops off, a momentary voltage spike occurs, too. The circuitry is supposed to handle that, but evidently doesn't.