Number of RF nodes connected to GW core module

At the docs for USB Dongle module is written that you can connect up to 32 RF nodes to it (due to dual security chip).
But how many RF nodes could be connected to the core module 1.x and 2.x with gateway firmware?
I tried to search for this information here and in docs but without success.
I want to use some GPIO pins at the gateway module, so USB Radio Dongle does not fit my needs.

some anwers are explained in this thread

The 16/32 limit is not fixed right now and you can change the define to bigger number right now.

In future we plan to use external security chip (right now it is not used) and every chip can hold 16 keys for 16 nodes. So in future there will be fixed limit for 16 devices with Core Module Gateway with single security chip and 32 devices for Radio Dongle with 2 security chips.