My hot take is that I honestly wouldn't mind if Milo also joined the paused campaigns. At the current point each story is at, it would be fairly easy to implement a new character in the same way WD was introduced.
Emizel could come across Milo's character while he finds his way to Shilo and Arthur in Romania after the time-skip. Similarly in Riptide, Milo's character could aid Jay's travel to the front lines of Lizzie's battle with the Navy.
Prime Defenders was a bit more difficult to figure, but her character could easily be a member of WATCH that was assigned to the same mission as them because some kind of special expertise, or a vigilante that stumbled upon the same case.













