The criteria for choice isn’t based on when the season finishes, but when you start and finish and athlete suitability.
If the SE isn’t in place at the right time, that’s a planning issue. BOTH L-to-S and S-to-L have significant Speed Endurance possibilities within them, as you can see from the two comparative charts. They are just achieved differently.
We opened up fast first time out from SPP2. that came primarily from SE maintained from SPP1 because there wasn’t that much time to get much more SE in place at least as we did it, reserving SPP2 for pure speed and SPP3 for extending it.
Those who choose L-to-S and sacrifice indoors are using a single periodization plan IMO.