Our plane typically changes itself as appropriate to the various RNP levels. For example, we do a lot of RNP-1 departures and it always seems to say RNP-1. Then at some point it will change to RNP-2 or we may be over the ocean and see that it is RNP-4(my last type went to RNP-12 over the ocean).
A lot of the arrivals are RNP-1. The aircraft only seems to change to RNP-1 as we descend through 15000' even though we may be on the arrival earlier than that.
RNAV approaches are usually RNP 0.3 and that has to be manually entered on our aircraft.
Bottom line, we only manually enter for an RNAV approach. The rest is automatic.If there is a problem, there will be a message for us.