Maybe I misunderstood.
You seemed to be saying that because you had reached such-and-such a level on the EDSS, that now meant it's more likely you have SP?
I don't think that's true, as the two things aren't closely connected.
It sounds, from your description, as if you are still having relapses. Recovery is incomplete, and you are left with some residual damage - which, unfortunately, tends to be the way it goes, in the long run.
But I still don't think the cumulative damage, in itself, is evidence that you must now be SP. This could simply be the effect of many relapses over the years. A relapse may be followed by complete recovery, but isn't always. If you do improve, just not completely, it's still looked on as a relapse, and not "progressive" MS.
I don't have days when I feel completely well, either. Various things keep hurting, or feeling "odd", or just don't work as well as they used to. I still don't see this as proof I've become "progressive", even though, like you, I'm convinced I had MS for many years before being diagnosed (10 or 12 is not unlikely).
I suppose I might already be SP, for all I know. If I'm right about how long I've already had it. And I haven't had a relapse for ages...or not one I was really sure about, anyway.
But anyway, as Woblyboy says, what's in a name, really? Slapping a different label on it after a certain amount of time, or a certain pattern is observed, doesn't mean the MS now knows what it's called, and has to behave accordingly. You still have what you had yesterday and the day before.
It doesn't "go anywhere" because it's been rechristened.