Hi, stobonet.

This feature is currently unavailable in QuickBooks Online. For now, you’ll need to update the custom field information manually. 

I’ll also make sure to take note of this feature and share this with our developers for future updates. I’m sure that other users would like to have this option as well. This can help us enhance your experience in QuickBooks Online.

Please let us know if you need anything else or have further questions.