But, even though it's late in this game's lifespan, as Spla2n is coming out in less than 2 months (jeez!), I would definitely try speedrunning this game
As I see it, it's never too late to Speed Run any game. There's always new time saving glitches and shortcuts being found on even the oldest games. I remember watching a Recorded Livestream Speed Run of Luigis Mansion (Awesome Games Done quick, in its hayday) and the Speed Runner noting how only recently at the time, A new time saving glitch/skip had been discovered that had never been noticed. For years. And only a newer Speed Runner had found it.
The hunt to find new breaks and new ways to navigate the games never have a true end I figure. The older the game, the more learned.
So yeah, some encouragement for folks along with your words here to give it a go. I cant say I'm capable of such speed running myself unfortunately, hah.