SAP ERP LE-WM Removal strategy M with 2 storage types

Dear experts.

Let me ask one question re WM removal strategy "M" (small / large strategy). I found some discussion but w/o clear results I can understand, so I am trying to ask again.

We have 2 storage types, one for pallets (open storage) and one for small quantities (High-rack), there is no SU management activated.

The requirement is to use removal strategy for picking (Outbound delivery) defines below with the example:

Outbound delivery item required qty: 350 pcs

Pallet qty: 100 pcs

Stock of pallet open storage 1000 for example; stock of high-rack for small qty 100 pcs

"M" strategy maintained for high-rack (small qties) and "F" for pallet open storage, searching sequence first define high-rack and open storage (for pallet) on the second place. Material master defined for control qty of 99 for high-rack, also palletization data is maintained (100 pcs for E1)

Assumption of this setting was the system will create 2 items of TO, first with the qty 300 from pallet open storage and 50 pcs from small qties high-rack.

But system creates only 1 TO item for 350 pcs from open storage type, no picking of small qty (i.e. 50 pcs) from high-rack ("M").

Is there a way to cover this process as assumed? Seems standard doesn´t work like this so only user-exit needed? If yes, is it enough to activate and create user-exit for pallet storage type (open storage) with "F" strategy?

Thank you for any kind of feedback.

Best regards,

Pavel