Gilberte,PRDH is the most accurate information that is available to me at a low cost.I live in Oregon and the church records are not easily available.I have sent for some for my long lines, Manseau, Lavoie, Ricard and Rioux.
Duplessis is not one of my ancestors.The first Duplessis (with children) to arrive in Canada was Joseph that got married in 1726 according to Jette.All my ancestors arrived in the mid 1600s.The only Duplessis that I have in my file of 18,562 individuals is Joel that married my great aunt Caroline Manseau in 1882.
I was just trying to help when I used some of my hits at PRDH.I know that the church records are the best.I also know that some of those are wrong because most people were not educated and did not care.For baptismals, the church did not even required them to use their father's original surname.Children from the same families were baptised with different surnames. That is why PRDH and I beleive it is important to record all "aka" names for genealogy purposes and make notes of the information we find in records.
By recording both names, I have found it easier to trace my ancestors.My Jacques Manseau-dit-Robidas is a perfect example. I am a Manseau, yet I have been able to help many of my Robidas distant cousins find their ancestors. There was another Jacques Manseau that arrived in Canada in the 1600s.His decendants are not related to the decendants of Jacques Manseau-dit-Robidas.
If PRDH uses double names I would do the same as in"Noble Duplessis".The genealogy of Québec is great, but it is not a pure science.
PRDH will change their records if you send them proof.Since you have done an indept study of the Duplessis you should send them your findings. Their birth and marriage records do not go into the 1800s.Quite often they will make a note on their records, even if they do not change the original ancestors name.They will also record the people that attended the event if they have proof.