Since you are using the manufacturing module, try out the module: MO and BoM variance whose author is intelliVersal integrated solutions. This module generates a variance analysis report showing the quantity and cost differences between BoM and actual MO.

I don't think it is possible to add worksheet.  But with steps it can be done.

We did some customizing with Studio app to add steps to an existing work order. You have to modify the list view for finish steps to allow to add steps.  You need the quality app to add steps, and there is a setting in Configuration in the manufacturing app to add steps in a work order.

Create a quality control point with test type Instruction. And step document should be custom.  Add this to the operation.  But leave it empty.  You can then open the control check in the work order tab Finish Steps and upload a document.