If your GPS will hold all 5 days of course at the same time without issue then great. Mine do. Some do not.
SCORE was always careful not to have any trails with more than 9999 track points due to common limitations of GPS units. For example, the 2017 Baja 1000 file I saved contained 10 tracks, the biggest with 9855 track points.
Another factor with NORRA is sometimes you come into a town on a track then the next day depart backwards on that same track. This could get confusing if you load all 5 days at once and are just following the line instead of paying attention to where you are supposed to be going.