Remember that RNP is a specific requirement for the airspace you are in. There is no need to make the RNP low if the traffic density is low and there are no obstacles to consider.
Why make the procedures overly restrictive if it isn't needed?
The P-RNAV concept was and is only a stepping stone to RNP. The arrivals are designed with rnp 1 in mind to best meet flow demands and obstacle requirements.
In the honeywell Primus epic FMS the default values are .3 Approach. 1 terminal and 2 En-route changing to 10 in remote areas. These are just the default values set by Honeywell they have nothing to do with the actual RNP values for the airspace you are in. For example B-RNAV requires RNP 5 but the default value in the fms is RNP 2. Either you leave it and accept an alert for the wrong value or change it to reflect the actual requirement.