How to change Valuation Type of existing Item with submitted transactions

When we started the development with our client, there was no batch wise valuation implemented, and we experienced bugs with FIFO, se we decided to go with Moving Average.

Now the client is asking for Batch-wise valuation.

I know ErpNext prevent changing the valuation type in the Item:

But still the client is king and wants it :slight_smile:

So, what would be the implication of doing this change manually with some scripts ?
Anyone did this in the past ?

We are willing to pay for this service if someone has knowledge on the how to.

Thanks !

Someone can help me ?