[IMP] mrp: usability of BoM (lines)

- Task: https://www.odoo.com/web#id=10010&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.FJILGyANBSVkazkw
Hi @odony and Odoo team. Here is my aproach about this point:

I see 2 different concepts on "phantom" configuration. 
First one on sales for kits, is needed usign MRP bom object to substitute main product for components on picking (This is an usability issue since I have got to install MRP to use kits on sales even if company is not using MRP/MOs at all, I think it could be a little bit improved, I don't know)

In manufacturing, it's needed to substitute main product in "planned components" on MO
Only sales is using "phantom" concept on BOM header, since in manufacturing, component line is defining if a component should be sustitued or not. I mean... supose this bom:

Final Product marked on header as phantom, having
    component1 as normal on bom components
    component2 as phantom on bom components

On Sales we need to search for phantom or normal bom on Final product in order to be or not substitued on picking
But in manufacturing, I don't mind if final product bom is marked as phantom or it's not, since I could anyway launch an order for Final product, using phantom BOM and this is perfectly working righ now. That is his header configuration doesn't mind in manufacturing for main product.
But, when planned materials are calculated for Final product, just the components marked as phantom would be sustitued for its own components, On our example below  only component2 will be sustitued and again It's not needed that BOM for component2 is marked as phantom on header, just a "normal" bom could be used perfectly to replace component2 itself by it's own components in MO.

So.. for me header field should be used to determine if the product must to be replaced for it's components or not in sales. And bom line component should be used to mark if component has to be replaced in MO. 
Both could be check fields, both could be selection fields as it's now. Never mind.  

As it is now, it's working fine I think. No problem with it, but it's true that maybe for a newbie is not very clear how it works. 
My2cents