Good news, this is now live in Breww 
Customer lists can now run as “workflows”, so there’s no need to add a task to each customer. Choose how often a list is worked through (e.g. a call list with a set day each week, over each week or over each month), and Breww opens a fresh checklist of the customers on it each period, with a single task for the people assigned to it. Your team works through it from one page, marking each customer as completed or declined, and logging calls, updating details and creating orders without leaving the list.
Full details are in the announcement: Customer list workflows and preferred contact times: work through your customers regularly, at the right time for each
Thanks for requesting this, and we hope this helps!