Split milestones 3 & 4 into (3.1+3.2) & (4.1+4.2) for individual devs, as my part of the Milestone 3 (3.1) is done, 4 (4.1) is reachable in a reasonable time as well.
My parts of 3 & 4 deal with being able to perform the same tasks using simpler solutions, yet requiring more initial time investment from the User.