Note that at least one movie (
[1570] DS Space Invaders Extreme 2 by FractalFusion in 07:56.48) takes the hardest/least optimal route, in order to make the run more entertaining. I suppose what happens depends a lot on what routeplanning does to the game, and in particular how interesting a choice it is in the game in question. In games where routeplanning is difficult, finding a faster route is an important improvement, and suboptimal routes tends not to be too interesting; in some games, the difference between routes is obvious but only fastest/fastest without glitches/100% categories are interesting, and routes that aren't optimal for one of those are rejected (e.g.
#2976: Kaylee, MICKEY_Vis11189, Moltov, Nahoc, SilentSlayers, snark, sonicpacker & Eru's N64 Super Mario 64 "16 stars" in 13:28.40 was rejected for goal choice). There's definitely scope for "suboptimal" route choices if you can find a category where they're optimal, though (such as playarounds, hardest-route/best ending games, and the in-game time/real-time distinction); although only the most entertaining few categories tend to be allowed for any game.