If Advanced warehousing is turned on, Pick + Forward flushing method does not exist as a concept in manufacturing. There is no way you can create a warehouse pick prior to the production order been released to the manufacturing floor (not at Firm Planned). You would have to create something like a movement worksheet to get the items from the bins to production bins first but this is quite cumbersome when you've got a large quantity of items required for each production order. Therefore I would argue that the concept of having a Pick + Forward flushing really doesn't exist.
The pick worksheet does not work for film planned production orders either in case that may be a suggestion.
I would also argue that the forward flushing method is only useful if your components are in your production bin.
