So, I think I figured out the confusion here. On the web version, when creating a custom nozzle the software requests a "flow rate".
However, the mobile software (Android or iOS) requests a "PRECIP" figure. Assuming this means "Precipitation Rate".
Reviewing the support article here, it appears that "flow rate" and "precipitation rate" are used interchangeably. However, these are NOT synonymous terms. In fact, there is another support article titled How do I calculate my precipitation rate? which states that "Custom nozzles use the precipitation rate (PR); but this is not the same as the flow rate." The circular logic here is that precipitation rate USES flow rate in it's calculation, and thus by logic they must be mutually exclusive of each other. One could not provide a true FLOW RATE in the software as there is nowhere to under the number of heads/emitters. Thus, if this truly should be a PRECIPITATION RATE entry, then it should be renamed as such. I shouldn't have to assume this as they are different.
My recommendation, however, would be to use a FLOW RATE metric AND # of heads/emitters. This way, the already-entered square footage (area) measurement can be used to CALCULATE precipitation rate. Furthermore, the "nozzle" should identify a SINGLE nozzle and NOT the entire zone. By using precipitation rate, it's a "zone" setting and not truly a "nozzle" setting. Semantics, maybe, but either way it's quite confusing.