Hey there and welcome to the Community @Ken_Davis 
I completely understand your point and really sorry that the signature caption hasn’t been released yet.
Sure, our devs can definitely develop the signature capture feature. Right now, though, we’re focusing on higher priority requests. For instance, just yesterday, we released the highly anticipated feature for inviting team members to your account - Add team members to your account
Once we receive any news regarding this request, I’ll promptly update you here 
Thank you so much for sharing your feedback with us!