@Bastien_Siebman I hear ya! I think this is a great practice for clarity on work. Specially when involving an assignment!
That said, I’ve found Asana to be so flexible that I often track more than just “tasks”. While the core unit of measure is a task, you can exploit the platform to do so much more. The more you gravitate from a task as a unit of measure, the more I see a place for “Complete” as Custom Field criteria.
Even if you only use tasks to measure who needs to complete what and when, wouldn’t this still be an acceptable Custom Field for a portfolio?
I love @Paul_Grobler’s idea of having interchangeable simple rules. Where a change to a column will complete a task or vice versa (through a checkbox to operate in reverse). This should totally be #productfeedback if it isn’t already!