Custom task id takes a long time (according to technical support team - up to 5 mins) to be generated in the back end and to become retrievable via api. This is not acceptable as a work productivity tool - imagine creating a task and having to sit in front of your screen for 5 mins to wait for your custom task id to be generated (and subsequently downstream webhook automations such as folder creation with custom task id prefix to be created).

Much like many other posts here, native task IDs are not suitable because they are a jumble of random characters which is not helpful to end-users to organize their tasks chronologically.