Two-Factor Authorization on Signature Requests vs. Protected File

[KFTS]

Hello,

I know two-factor authorization on signature requests is only offered with the Enterprise edition.  I also see that evidentially, you cannot send a protected file for e-signature?  You are therefore relying on the actual owner of the email address to be the only one that would have access to the email.

Is there a work around or why cannot a protected file be sent for e-signature?  I have seen this asked back in 2017 but I could not find an answer.

Thanks, Todd