Sorry SOB, I have to go with WN on this.
I see your point, if the aim is to do the barest minimum of paperwork.
However, until such time as the Authority ( whichever it is!) approves the removal of a paper flight plan you have to compete the paper one.
So, we have to add up the times for 35+ points.....Awwww!
But hands up the man who hasn't spotted a discrepancy between paper and FMGS.
As I understand it the RETO is changed when it is the next waypoint.
For what it's worth, when I get a DIR TO I enter a RETO for that point, and I always select Abeams when I go direct. When I pass abeam a point I enter the ATO. it may not be required but it does help to avoid the old "Thumb in Bum....Mind in Neutral" Syndrome!