It goes by level and reputation. Just use the command
Player->SetReputation 0
And they shouldn't let you skip them. I think 50 is required to skip. But that's just what I've seen from this...
Taken from UESP
"If you are over level 20 and have 50 reputation, then you will not have to complete the Fourth and Fifth trials. Instead, Nibani Maesa (or the Dissident Priests and Great House Councilors) will tell you that you should see the Archcanon in Vivec High Fane right away."