Spring Training Schedules

[senbatsu]

Has anyone found a way to edit a spring training schedule without manually going through the in-game editor?

I have a fictional setup including every high school in Japan, and I wanted to add spring practice matches on weekends starting in May.

But the game generates spring training without referring to a schedule, and after the season starts, I can't import a custom schedule into the game that includes spring training games.

Is there any workaround beyond editing each prefecture's schedule by hand?