In the most simplified terms, it is the frequency that does the work. So if the frequency is resonant to devitalize a pathogen (kill), this is what it does regardless of which settings you use.
The healing preset uses settings that are more conducive to healing modalities, but can kill just as well if used with devitalizing frequencies.
The killing preset uses settings that are more conducive to killing modalities, but may detract from a healing modality.
The majority of Rife frequencies tend to be of a killing modality even when we might think otherwise. Healing modalities can be simplified to frequencies that entrain -- like Songs of the Spine which guide the spine back to a particular operating frequency.
Therefore, if you are unsure which preset to start with, you can always start with the healing template as it will work well for all situations, much like how the DH preset works for both modalities equally well.
Since you are specifically talking about biofeedback results, the majority of the returned frequencies will be of a killing modality.
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