Automate subitems dependencies and subitem due dates

When I create a new item, I’ve set up an automation to add subtasks but I want to be able to assign a due date based on the parent due date and automatically connect the dependencies.

So automate:
add subitem x at 10 work days before parent due date
add subitem y at 7 work days before parent due date and set x as a dependency
add subitem z at 3 work days before parent due date and set y as a dependency

It seems silly that you can’t automate dates for subitem based on the parent item date but I can’t figure out how to automate a date to anything other than “today” or a specific unchanging date. I assume this is because it needs a date for the automation to function but you could add a condition that the parent date needs to be populated for the automation to run. I tried doing it with IF statements which kind of works but then you can’t display those dates in a calendar view and I can’t figure out how to set the IF statement to include everything that needs to be in there to make it really functional.

Setting dependencies is also time consuming since you have to search through every item. It would be great to be able to drag to connect them (like how you can parent layers in After Effects) instead of having to do a search every time or set a function where you can select a list and automatically create dependencies based on their order.

Up on this. I have an average routine workflow where 1 item = 1 project. And within that 1 project (item) are some tasks that I need to do. I just want the subitem due dates to update automatically when I set the due date for the parent project (item), and it’s so frustrating to do.