That's a good idea. Zeldawock's one of my favorite quests, actually. Do you have any suggestions for quests with lots of collectible items? Maybe a very open-world quest where we could race to find the most equipment, or something else with lots of different stuff to find? (My own quest actually springs to mind here, but I wouldn't do that one for obvious reasons.)
There's the one metroidvania made by you, but that's fairly long.
There's Freedom in Chains, which is also a good one.
Passage Through Time would also be a good one, since that's fairly non-linear and was rather filled with sidequests.
Randomizer, maybe? Might not be good for speedruns, but definitely good for racing. BS was the shortest and best, IMO.
Link and Zelda when it comes out (which I think is to be out by the end of the year?), unless everybody raced the demo from the expo (not a bad idea), mostly because there is a lot of items in it.
ToTheTop for longer races, since the floor structure gives clear progress points.
Hookshot 2 surprisingly is a good racing quest, and I actually did a reverse dungeon run once. Either the old version or the new update would work.
Hero of Dreams had a few sidequests you could do whenever, so possibly that?
I can't think of any others off the top of my head.