Here are my thoughts. If one were using enough of the RS232 handshaking signals it would be possible to manually monitor the UART. yes

However, with the UART uperating in full duplex asynchronous mode, without the benefit of handshaking, the risk of missing something would be high. This IS handshaking, without the benefit of interrupts: yes

On the other hand, in the context of some limited applications it might be possible to write the code such that receipt confirmations were handled in software and the manual approach could be made to work. yes

So here's my question. Can one think of a time, a specific application or circumstance, where such an approach would be favored or worthwhile? no

Is there possibly a circumstance wherein one would prefer to handle the UART manually? Or is the hardware interrupt just too convenient? All reasons for handling the UART without interrupt are "I am afraid of interrupts". Some novices use non-interrupt UART control because "interrupts are too complicated". That of course, should not be the case in project #2

Erik