How to include timings within BOMs that do NOT change with quantity of production in Work Orders

Hello everyone,

I have been recently exploring the manufacturing module of ERPnext but have encountered a problem. I have a number of workstations/operation/item combinations that need BOMs with unique operation times. However, there are also setup times for these machines that need to be included in the time/cost estimations for these BOMs, but these setup times do NOT change if a work order is created for more items than what the BOM is set up for.

as an example: item A must go through a lathe for machining, and it takes 2 minutes per item. However, setting up the Lathe for this item takes 10 minutes. I need to be able to make a work order for 5 Item A’s, which would take 10 total minutes of lathe machining, but still just 10 minutes to setup (so total time of 20 minutes). From what ive found in creating operation tables in BOM’s, all operation times scale based off the quantity in the work order.

I have been looking but I can not seem to find a tool in ERPnext which accomplishes this. any help would be appreciated. thanks