Just as in airports, you have to pay some money to go till the security counters. After that only the passengers are allowed. Similar thing can be implemented here. Ticket would be needed to go till common area. After that only pax can go till the PF.
Over luggage in coaches causes huge inconvenience to pax.
Alternative of this can be implemented in shatabdi/intercities which are of shorter length. One luggage coach can be put between 3-4 coaches for luggage