Nintendo has patched The Legend of Zelda: Breath of the Wild in their latest update for both the Wii U and Switch. Both games get an upgrade to their framerate performance.
The update, clocking in at 170mb, has a very short description from Nintendo, only mentioning that it's a "more pleasant gaming experience".
The exact changes are unknown, but a number of people have mentioned fewer framerate drops in handheld mode and while docked, it seems ever consistent. A video has emerged on YouTube thanks to user ElAnalistaDeBits comparing the performance between 1.1.0 and 1.1.1:
