It's nice to see you again in the QuickBooks Community, gkski2. Let me provide details on how organizing your items is beneficial when creating invoices in QuickBooks Online.
Please know that separating Labor & maintenance on the invoice provides a more detailed breakdown and explanation of the costs. This helps your customer understand the specific amount of each service and item.
However, I still suggest consulting an accountant. They'll be able to provide you with suggestions on how to properly handle Labor & Materials, especially with the category or account to use for these items.
Keep in touch if you need further assistance managing your items in QBO. Please know I’m always ready to help and make sure you’re taken care of, gkski2. Have a great rest of the week.