Hi,
My question was not clear !
Until now, each time Ghost released a membership functionality, you had to update your theme to take advantage of the new features.
Eg : Routes.yaml etc…
Editorial Theme doens’t support natively memberships features but since few weeks “portal have been released” which make all themes compatible with members.
It’s working out of the box but you still have modifications to do (initial post).
So I’m trying to assess the effort for this option (Editorial + Portal) versus a native theme for this feature (Lyra, Pico, Alto etc.) 
Eg : Pros & Cons
Happy Holidays everyone!