It is managed by ESP32, so it is going to be something very minimalistic on level of FreeRTOS instead of big Linux distro.

Which means that if you know how to program ESP32 and setup the RTL8372 switch you can have massive flexibility with it. If you don't, then you are stuck with whatever Ubiquiti firmware is being run by this switch.

It's just an ASIC switch, not a SoC.

its basically AISC plus microcontroller - https://svanheule.net/switches/rtl8370