I would also recommend using price control S for raw materials when actual costing for finished goods is used.
The reasoning is the following: actual costing for finished goods is a "period average" concept.
When using price control V, those period averages are calculated with raw material prices that vary during the period, while using S for raw materials also averages the cost of raw materials during the period. This seems a more consistent concept to me.
Moreover, price control V can result in very strange behaviour of the moving average price, especially when errors in the price of purchase orders are involved (oops, entered 100$ per Kg instead of 100$ per ton). This may result in very incosistent actual costs for different finished goods using the same raw materials. Price control S ensures much more robust realistic periodic values for raw material costs.
Regards
Nikolas