It would be very useful to have the ability to create subtasks for clients in the same way as we can for internal tasks.

My most common use case is for onboarding. in my onboarding project, I want the onboarding steps grouped together in an intelligent way (Billing Setup, QBO Setup, Dext Setup, etc.) and I am currently creating task groups for each of these. The downsides are that we have to go through each group and send them one by one to the client, but more importantly the client gets a different email for each group, which can end up being about 5-10 emails at once just for onboarding. Not the look I'm going for.

A better setup would be one onboarding group (or at least anything you want to send at the same time in one group) and then be able to create subtasks so that the client receives one onboarding email with everything they currently need to do, logically set up as tasks/subtasks.