question

I'd suggest to use a process flow to control the item transports. Using only 3D logic to achieve the goal is certainly possible but probably more complex at this point.

In the attached model, a new token is created each time an item enters one of the queues. These tokens are then batched together up to the batch size setting of the queue. After the batch is full, the released token acquires both a destination queue and operators. These are implemented as resources, so only one token (queue) can use them at a time.

The operators are then told to transport the items. When they are done, the queue and operators are released again.

When acquiring a queue, the condition that there must be enough capacity for the batch items must be fulfilled. That capacity is tracked in a label on the queues. When one is acquired by a token, the capacity is decremented by the amount of items in the batch. It is incremented again in the "On Exit" trigger of the destination queues.

configuracion-6-op_1.fsm

I hope this is what you had in mind.

If you haven't worked with process flow before I'd suggest to work through the corresponding tutorials in the manual.

Basics 1.3 https://docs.flexsim.com/en/21.2/Tutorials/FlexSimBasics/1-3BuildProcessFlow/
Basics 1.4 https://docs.flexsim.com/en/21.2/Tutorials/FlexSimBasics/1-4LinkModels/

PF Shared Assets https://docs.flexsim.com/en/21.2/Tutorials/ProcessFlow/Tutorial1UsingSharedAssets/UsingSharedAssetsOverview/

If you have any questions about the attached model after that, feel free to ask.