Grant,

> What would you do with the serial connection that you wouldn't / couldn't
> do with a direct Ethernet connection?

Its the other way around: what can't you do with a serial connection that
you could do with an ethernet one.   You wouldn't be able to portscan just
any other 'puter in search of a vunerable service.

>> I just realized I should take a peek at USB-to-RS232 converters.
>>  Those might well have a much higher thruput than what the UART offers.
>
> I doubt it.

Doubt no more. As an example:
https://www.sjoerdlangkemper.nl/2019/03/20/usb-to-serial-uart/#chip-differences

>> That being said, you could probably find USB-to-> RS-232> that will be faster.

Yep.  Something called an "USB Bridge".   But as I read that it might be
supported by the OS as just another network interface it would do exactly
what I don't want. :-|

Regards,
Rudy Wieser

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