Steps to reproduce:

1. install Zabbix Server and 45+ proxies
2. use Proxies to monitor something, for example using simple checks with lot's of dependent items

Result:

1. preprocessing manager consumes memory and also performs some processing, in log of the Server we can find information for items/dependent items which are not processed by Server itself:

   2952488:20210714:072909.721 End of DCconfig_get_preprocessable_items() items:1075511
   2952488:20210714:072909.721 End of preprocessor_sync_configuration() item config size: 1075511, history cache size: 3
   2952488:20210714:072909.721 In preprocessor_enqueue() itemid: 920540
   

Expected:
If items are not processed by Server it's not necessary to shadow information on Server, since can use lot's of memory on a busy setup and also this can create additional locking.