Only indirectly related, but it's mildly amusing to see UART backpressure addressed when most serial ports these days are wired up without CTS/RTS, and no XON/XOFF either.

(I break out CTS&RTS whenever I can, & so should everybody else. You don't have to use it. Just route it to wherever the serial ports goes.)

Good point.

A lot of small setups don’t wire CTS/RTS these days, so I wanted to explore a software-side approach as well. But I agree, proper flow control is still very important.