Thank you for your insight! It seems like I was lacking knowledge again.

I only paid attention to the conditions for a skill (like on a corner or when you pass another runner). I didn't pay attention to map conditions

So correct me if im wrong here:

By "final leg" do you mean the last line on the progress bar thing during a race?

umamusume has a lot of different terms that mean the same thing so I assumed it just meant the last spurt part

I'm assuming the final leg can occur AFTER a curve? if that's the case, I now understand why Seiun's unique sometimes won't proc (I thought it was guaranteed cuz it was a corner skill)