Thank you very much, really helpfully your answer.
Good to know that I can use any GPIO as third UART.

I'm designing my own board with some devices connected by UART to ESP32-S3-WROOM-1-N4
I'm basing my board design on ESP32-S3-DevKitC-1 v1.1.
As I read on documentation, there's 3 UART ports, but I just can identify 2 of them.

ESP32_S3.png

On GPIOs 43 and 44 there's UART0 (U0TXD and U0RXD)

On ...