Super Mario Odyssey Downgrade Digital Version to 1.0.0 or 1.1.0

Since the cartridges don't change version like in the N64 days, you have 2 choices. Starting at 1.0 on a wifi disabled switch with the physical game; or playing on the latest version on digital/wifi enabled switch.

The only way to play 1.1 (or any version between 1.0 and latest) would be to

1. Emulate it
2. By some kind of sorcery flash your own cartridge with a 1.1 rom.

Both options seem like pretty hard to do as of now. So I would say you will have to give up. The records that are recorded in the 1.1 version are now pretty much untouchable and skips/glitches that were available only in the 1.1 version are now unusable.

This should help you (https://www.speedrun.com/smo/guide/qbeq4, Credits goes to Smallant1):

HOW TO GET 1.0.0:

There are two methods currently that do not require "hacking" your switch to obtain 1.0 and keep your save files for other games

METHOD 1 Requirements -Physical Copy of SMO with serial number ending in 000 -Willingness to temporarily lose access to your SMO save data -Nintendo Switch Online

1. Backup the save data for all of your games on your switch using the Switch Online Cloud Feature
2. Factory reset your Switch.
3. Start up your Switch (DO NOT ENABLE INTERNET YET).
4. Turn off auto-updates.

At this point, you can play SMO 1.0.0 and have no problems whatsoever, but you don't have your save files back, so...

5. Turn on internet.
6. Redownload any games, and save data from the cloud. DO NOT download your SMO save data. If you download it then the game will not start without forcing an update first.

You can now play Mario 1.0.0, but every time you try to boot it up it will show a dialog box that will try to get you to update. You do NOT have to do the update, but the box will still show up. Unfortunately, any games that do not support the Cloud Save Backup will have their save data lost. Keep this in mind. (Splatoon 2, Pokémon Let’s Go, NBA 2K19, FIFA 19, Dead Cells, Dark Souls Remastered)

METHOD 2 Requirements: -Physical Copy of SMO with serial number ending in 000 -Willingness to lose your SMO save data -A second Switch (Only necessary if you wish to keep save data for other games)

1. Delete Mario save data from the profile(s) you want to "save" for later.
2. Transfer the profile(s) onto another Switch (not necessary if you don't care about other games save data).
3. Factory reset your Switch.
4. Start up your Switch (DO NOT ENABLE INTERNET YET).
5. Turn off auto-updates.

At this point, you can play SMO 1.0.0 and have no problems whatsoever, but you don't have that profile yet, so...

6. Turn on internet.
7. Transfer your user profile back to your Switch from your friend's Switch.

You can now play Mario 1.0.0, but every time you try to boot it up it will show a dialog box that will try to get you to update. You do NOT have to do the update, but the box will still show up.