Just want to give an update here because it has been some time since the last update came though, I'm sorry about that. This is still being reviewed, and a problem that we plan to prioritize this year, however, it will likely come later in the year, so I am updating the status here to Not Currently Planned.
We see a lot of value in solving this issue, especially in cases when folks are working from an email client. Once we have solved some core issues related to managing enrollments and reporting, we plan to priortize solving this problem.
I'm updating this idea to "Being Reviewed". We're looking into a few variations of "replying with a sequence" and from some of the use-cases in your comments and from some customers I've spoke with, it sounds like there are a couple of ways folks think of "replying with a sequence".