Warehouse Picking Process doubts

Generally we activate the Warehouse flag at P4210 option and once we created the order the order will go on ** hold and warehouse request has generated .

But is it possible to activate the Warehouse process and Pick request generation apart from P4210 ?

Actually i want to apply warehouse at my existing business process where i don't want picking process should create at order creation as we have some additional process included after order creation . so once all these additional steps are completed then i want to start warehousing , so is there any standard way

Check the below screenshot where at second stage i.e. Routing plan process where actually Warehouse BP decided hence after this steps i want warehouse process need to start .