Which change during operation would have little impact on safety and effectiveness?

The option regarding moving to another mixing/loading location would have little impact on safety and effectiveness because this change primarily relates to the logistics of preparing the application rather than the actual process of application itself. The safety and effectiveness while applying chemicals depend more critically on factors like application speed, altitude, and flow volume, which directly influence how products are delivered to the target area.

In contrast, changing the application speed can affect how evenly and accurately a product is dispersed, while adjusting the altitude might modify the rate of drift and coverage, and altering flow volume can influence the rate at which the chemical is applied and its effectiveness on the target. Since mixing/loading is a preparatory step that occurs before the application begins, it generally has a lesser impact on the ongoing operational safety and application effectiveness compared to the other options presented.