The only GL Account that really matters for expense items such as supplies is the first one.  They are going to be type N (Non-Inventory) items expensed at the time of receipt and never sold or used in work orders so the other accounts on the Item Class screen do not matter.

Items that are part of what are being produced are NOT expenses. they should be going to the Raw Material Inventory Asset account.  The COGS account for components is the account what will be posted to when adjustments are made during physical count and the Sales accounts would be hit if you ever sold a component (as if for a spare part or something)

The GL account that is expensed ( as well as the asset account that is debited) is controlled by the class code for the item.  The item type doesn't matter. An N type can be debited to an asset account when purchased if it has that in its class code.  This can create havoc if you are comparing your GL asset total to your Inventory value which doesn't give N types any value.
When you make your new part number, give it a new class code or temporarily change the class code you want to use -- change the COGS account to the expense account you have been using for the N type.  When you do an adjustment to the new part, DBA will credit the expense account and debit your RM asset account.  Then change the COGS for the class code back to what it should be for RM.

PS YOu don't need to do anything to the N type since DBA doesn't keep track of how many there are or what the average cost is.  All N type parts have presumably been expensed and don't count and so you don't count them either!