Allow multiple TFA registrations per account

This is an interesting idea. Are there any examples you know of sites that allow people to create multiple TOTP seeds? How does the end-user indicate which TOTP seed is the right one to use at a time.

Multiple TOTP installs is achievable right now, the user just needs to copy the seed to multiple places/devices. The same seed installed different places means each place will generate the exact same TOTP code (related #2483597: How do I set up more than one application?) Different seeds is a different story though would require a new feature.

Also, it's worth highlighting that this goal is somewhat handled by the various fallback methods. A user can have TOTP set up as well as SMS and fallback codes. #2478307: Allow user to decide which method is primary will make that easier.

I can't really see the advantage of having multiple seeds. As @coltrane said the same seed can be used on multiple devices, so device loss is not an issue, especially with fallback plugins set up.
Disadvantages would be a more complicated setup, and with every seed added the probability of guessing the verification code right ~doubles.

I'm voting for a "works as designed" or "won't fix" on this one.

Besides some setup text informing the user they can use the seed for multiple TOTP applications I'm of the opinion that there is little need to develop workflows to support setting up something like multiple TFAs. If someone is willing to propose a patch for the TOTP plugin to say something like "save the seed for backup or enter into multiple applications etc" please do otherwise I plan to close this issue.

Actually I'm going to close this issue as a duplicate of #2483597: How do I set up more than one application? and transition that ticket to be about viewing the seed with text about installing to multiple applications.