DE has already implemented that as we can play Octavia's quest and both cinematic quests , so why not do it for all the other quests ?
I would also like DE to let us get the blueprints from the desired warframe when replaying the quest in question , as for now , I cannot get either Atlas or Titania anymore without paying a **** ton of platinum which would just be a waste of time and/or money
I honestly do not see any issue with that aside from the fact that you can sell those blueprints , but then , the time spent in these quests is too much compared to just farming credits anywhere or if you guys REALLY don't want that , then just lower the price to 1 credit after people have sold it once.