Selecting multiple subitems from multiple items

This program has worked wonders for our organization but I feel as though there are some things that can be streamlined or modified to increase efficiency and accuracy.
I have been using for many things but my newest project is running a high level accruals board to track cost for each job/event. I have been utilizing subitems to list by billable items. Under the sub items am selecting a start date/time with an end date/time which then total hours is determined. I cant tell you the hours it would save me being able to select 30-50 subitems under different items and be able to change them to all the same start and end time. This project incorporates 8 boards with many custom integrations and sub items play a large roll in its success.

Is this something that is eventually possible to accomplish?