Add new Templates to existing Drips and have them work. Its crazy we cant do this!!!!!!

Im blown away that we cant add new templates to an existing drip  and have them work for already assigned clients, IE add a Day 25 email. And for all clients that have not hit Day 25 they would receive the email, Now you have to cancel and reassign the drip to each contact but that means they will start over which is crazy unprofessional. Im always modifying my drips. Adding videos to the emails, adding new content etc.   All big CRMs do this Active campaign, autopiliot, Infusionsoft, DRIP, Mainchimp etc