Hi there,
Subitems Pro Automations app can help with that. You can use the following automation to copy parent column to all subitems:
If you’re looking to copy a value to specific subitems, you can set up a connection using connected boards and mirror columns. If find a mirror column on subitem hard to work with, you can use a following automation to copy it to standard subitem column:
If you have any questions or requests for custom automations, feel free to reach out to us!