Multiple manufacturing plants and supply warehouses

We are looking for functionality relating to manufacturing items at multiple plants and supplying them from potentially another using 1 BOM. 

Scenario: 

• We are using 1 x Parent SKU
• It can be made in 3 x Alternative locations of manufacturing plants (warehouses)
• We only have 1 x BOM which is used for all 3 plants
• We have 3 x labour resources (1 labour team to be utilised for each plant)
• Each plants can be instructed to build on behalf of another plant requirements pending a decision made by a person on the sales order. We are using the terminology of Build From, Supply From. 

Build From Definition: 

• This is where the production order will be created for
• This is where the item on the order will be receipted into inventory
• This is where the BOM items for this work order will be backflushed from
• This is where the routing/labour resource is selected for the work order. 
• This also drives the child assemblies orders to be built and backflushed in the same build location

Supply From

• This is the warehouse field (Whse) seen on the traditional SAP Business One sales order. It defines where the sales demand will appear in the BEAS Order Recommendation regardless of where the item is going to be built.

Attempted Solution:

We have attempted to solve this scenario by using Beas Item Versions. With this, we can create a mirrored product/s relative to each plant. 
This gives capability to default the following;
- The receipt warehouse of the work order
- The routing and therefore labour resource team to be assign the work/affecting capacity
- Backflush items in the BOM from the correct plant (as each bom warehouse is defaulted)

An example of our setup is below. 

Issue: 

While this setup provides a general functionality required, it is terribly inefficient to setup and maintain. It is not a scalable solution and requires multiple bills of materials. 

It would be extremely useful for our current customers and future customers that there is a way of defining a build and supply plant for those multi-plant businesses. Ideally within MRP and driven by selections on the sales order.