With the split run SE in the early phase, I figure it’s a bit too close in effect but that may be habit as much as anything- trying to get one part down pat then then maintain the affected area (FEF,EFE mostly 0-30m and 60s and flying 20s 0 to 60) while trying to advance other very demanding qualities (mostly 80 to 120) in the limited time available.
The original qualities are maintained by starts to 30- usually 4 reps at the start of all speed sessions, and the 60 portion maintained by reps on the way through to 80 and, to a lesser extent, 100.