How to control flow mode out based off quantity?

I have a FFS where M1 feeds/supplies 4 storages.  These storages then feed/supply M2.  When the simulation starts, M2 has an initial delay to allow the storages to fill up.  Is it possible to set flow mode out on the storage based off quantity?  If the capacity of storage A is 10, but I only want to transfer 5 parts to M2, before starting transfer from storage B.  The same situation would apply for storages B, C & D. My initial thought was to use sequencing on M2 but the product/parts in each storage are the same parts, so I do not think this would work.  The same parts are being routed to different storages for various reasons.

Also, is it possible to stop M1 from transferring parts to a storage after initial capacity has been met?  Example: storage A has a capacity of 10.  After 5 parts have been transferred from storage A to M2, M1 will try and fill storage A to capacity again.  After the initial capacity has been met the first time, I do not want any more parts being transferred to the storage.

I am very new to using this software so any help & specifics would greatly be appreciated!

Thank you!