A sub-max flying sprint is just a way to build up to sub max speed easily to work on good form. That can be done anytime. Speedchange (FEF, EFE) is great indoors since SE demands are lower when the emphasis is on 60m.
In this case, with limited time to stretch out the SE, you need to spend most of the CNS energy perfecting that area. Hopefully, the speed change has already helped enough in the previous phase.
If you have a longer development timeframe before the meets get going in earnest, you can spread things around as you prefer.
This is just my preference under this particular circumstance. It’s always a balancing act.