Apparent aging and Magical Defenses

If a character has access to Magical Defenses against aging, and they're under 35, should they still roll on the Aging Table as if they were under the benefits of a longevity ritual, for the purposes of avoiding apparent aging?

Ex: A 25-year-old Persian sahir has Solomonic Alchemy and Solomonic Physic at 6, plus Magian Lineage. Should he be able to make his roll at -3 (-5 +2 for 20 years) minus living conditions to see if he stays apparently 25 for another year?

I'd say so, yes.

They are mechanically equivalent after all.

Yes, but it is optional. If you want an older looking character you dont have to perform the early rolls.