ESIGN is not ambiguous, it is flexible. Not a single word has been changed since it was enacted in 2000: "...the consumer...consents electronically, or confirms his or her consent electronically, in a manner that reasonably demonstrates that the consumer can access information in the electronic form that will be used to provide the information that is the subject of the consent." It's supposed to work just like the behind-the-wheel part of a test for a driver's license. The law doesn't care what kind of a vehicle you drive or how you drive it--so long as you demonstrate that you can do so in a manner that is safe and complies with all the rules of the road.
The most common ESIGN error is reading the word "demonstrates" and understanding it to mean "declares." To the best of my knowledge, the concept of a test drive or handshake is not found anywhere else in the all the laws and regulations applicable to financial institutions.
Vendors have a vested interest in peddling what they have created, even if it's trash. They always tell you that their services comply with every known law and regulation. How many times have you found vendor claims to be exaggerated or false?