Disabling switch online rewind function

Solution 1:

Now you can, with the inclusion of Button Remapping in Switch's system update 10.0.

Instructions:

1. Go to System Settings -> scroll down to Controllers and Sensors
2. Select Change Button Mapping (second option)
3. Click on "Joy-Con (R)" if you're using Joy-Cons, or a controller of choice
4. Press Change
5. Select ZR (top-right)
6. Scroll down and remap it to ZL Button
7. Click Done and OK on popup message

This will effectively change ZR to function as ZL, giving you two buttons (ZL and ZR) that both generate the same input (ZL), rendering the rewind shortcut ZL + ZR unusable!

You can save this as a Preset in the Button Mapping settings, and turn it on and off as desired -- e.g. turning it on when playing NES/SNES Online, and turning it off when playing other games.

Side-Effects:

• You will NOT be able to use the Suspend Menu at all, which means:
• You will NOT be able to save/load Suspend Points (aka saves)
• You will NOT be able to exit out of the game to select another NES/SNES game (you'll have to either turn off the button remapping OR restart the software)