I wanted to do a max score speedrun until I realized how long it would take me to do so. For the people who do not have enough time to do a Max Score speedrun, this run might be perfect. Some variants could be:
Yoshi's Island 2 only.
World 1 only.
Pacifist.
No Coins
No Dragon Coins
No Cape
No Powerups (Yoshis included)

The Max Score world record is about 15 minutes: https://www.speedrun.com/smwext#Max_Score, which is actually not a long time.

Those run variants you provided already exist in some capacity.
YI2 only: 0-exit (https://www.speedrun.com/smw#0_Exit)
World 1 Only: World 1 (https://www.speedrun.com/smwext#World_1)
Pacifist: 11-exit (https://www.speedrun.com/smwext#11_Exit_Pacifist)
No Coins: 11-exit (https://www.speedrun.com/smwext#11_Exit_No_Coins)
No Dragon Coins: A No Dragon Coins run seems redundant to no coins. A run that collects all the dragon coins in world 1 is Obroe% (https://www.speedrun.com/smwext#Obroe). The long variant is called Lunar Dragon (https://www.speedrun.com/smw#Lunar_Dragon)
No Cape: 11-exit (https://www.speedrun.com/smw#11_Exit_No_Cape)
No Powerups: This is Small Only (https://www.speedrun.com/smw#Small_Only)

Some of these runs are around the same length if not longer than the Max Score run.