Hey congrats, looks like a cool tool.
I wonder why you don't have "marketing" or "sales" as job options in the sign up flow, as I would suspect they would be some of your users.
The AI sequence builder is great starting point. I wonder if you would consider adding something to the UI to call out where the sender could add a bit of customization/links. I only wish you provided the option to reply to the previous message vs. adding the RE to the subject line. Guessing that is on your roadmap tho :-)