If I can tag onto this, I have a Forms process that will usually be kicked off by an external anonymous user but we have to provide a paper option for them to fill out as well. In the case we are provided a paper copy, a staff member (authenticated user) will enter the information via the internal forms process. We don't want them going to the external side to do this because we need to track who is performing the data entry, plus we provide additional functionality on the form based on if the current user === 'Anonymous User' or not. So having the two draft link options to use dynamically would allow me to enable the save draft option on this process. Our public users have been asking for it but I haven't enabled it because our internal users need to save drafts as well. Hopefully this flexibility can be included in a future Forms release.

Add the FormsHostEmailOverride option won't cause the internal users not be able to save draft or can access the draft without authentication, it will just affect the link they receive in the draft email notification and as since the draft can only be accessed by the user who save it, so even they access the Forms site using the external link, they still need to enter their credential in order to access the draft and Forms can still record who submit the form as they are authenticated.  

That's good information to know, thanks Xiuhong!

This might come down to our use case being too specific. I'm sure that solution will work for a lot of organizations. Our LF users are tied to Active Directory in our domain, our external instance of Forms lives in the DMZ, and AD is not accessible in our DMZ. Again, that may not be the case for other folks, it may be that our specific network is set up funky. If our users were to get task and draft emails with links pointing them to the external instance, they would not be able to authenticate. I considered implementing your solution and just training our staff not to use the link, but I think it will cause more confusion. 

Thanks again for your help! I will save this post in case we make network changes in the future that would allow us to utilize this option. Or if you have any other suggestions in the meantime, let me know 

If you don't have FormsHostEmailOverride option added, by default, the Forms server link in the save draft email notification should match the Forms server URL user access as Forms grab that from the user's http request. For example, if you access it with http://DMZFormsServer/Forms, the link in the save draft notification should be start with http://DMZFormsServer/Forms, if you access it with http://internalFormsServer/Forms, the link in the save draft notification should be start with http://internalFormsServer/Forms. You can test this in your environment.