Hello!
If you want to change the linked account on your Switch, it shouldn't affect your ability to switch back to Jailbreak mode. However, if the previous account had any digital games or saves, you might lose access to them when you unlink the account.
To link a new account and delete the previous one, you can follow these steps:
1. Go to the System Settings on your Switch home screen.
2. Scroll down and select "Users."
3. Select the user account that is linked to the previous account.
4. Scroll down and select "Unlink Nintendo Account."
5. Follow the on-screen instructions to unlink the account.
6. Once unlinked, select "Add User" to create a new user account.
7. Follow the on-screen instructions to add the new user account.
8. Once the new account is set up, you can link your new Nintendo account to it by going back to "Users" in the System Settings, selecting the new user account, and selecting "Link Nintendo Account."
I hope this helps! Let me know if you have any more questions.