Something minor, whilst clicking my retainers one by one.

While obviously they can't be too smart or complex.

Having the option to have the retainers be sent on repeat could work. The items they collect will be stored on their person.

or different but better yet.

If combined with the original idea.
Have the Venture Tab have a collect all, and resend as same task.(With said option to temp lock some retainers as repeating a task.

So say if you're farming crystal or decided to change up a specific item you are in need of farming.

Then those will still end up adjustable if you cap on said item or not.

Course it would have be as simple as possible. Cause there are limits when something has too much effort innit.