FYI: They’ll have to provide their email to DocuSign in order to verify their identity--even if they don’t tell you what that email is.
In my experience, a Powerform is just a shmancy UI for filling out an envelope but making it look more modern. The main thing with them is that yes, they can be a standing link that you broadcast/post/include in an email signature, and also that users start the signing process whenever they want rather than the having to receive an invitation email like with a typical envelope.