So you are going to put a percentage of content as "side-content" only there as a crowd-pleaser, that can or not be done?
My question for you, is why are you doing that to yourself? Is that side content that important that it will bring you subscribers? In that case, is it truly side content? If that's the case why isn't it the main story? See where I am going?
Bethesda can pad Skyrim with hours and hours of side quests, for them is par-for-the-course, can you justify delays in the story "because I was doing side things that count for nothing" on a tight schedule as you have? In that case, who will have the priority? The side content that is just there to pad the bottoms or the main story? If it is the Padded bottoms, again, why isn't that the main and so on...
I can kinda see what you are pointing at, but that will hurt development. Players coming for the "quick short fucks" will clamor for more, hurting the main story. People like me will have to wait forever to see any real progress, because the story is no longer a priority.
Even if triple the output. No matter how you slice it. It will never be a satisfying experience.
However I pick this, all I can see is your project getting hurt. Oh, and you can't serve 2 masters, it will NEVER work.
Peace