Ooohhhhh…Well, at least it was an honest mistake.  Thanks for pointing me to the correct playing field.  Just makes me question my day 1 logic class reflexivity principle.
HAProxy != HAProxy
:o
I do believe, though, that you could still legitimately call DSR products "proxies", they're just L2 proxies.  I mistakenly assumed that checking the Transparent ClientIP box in pfSense's HAProxy implementation turned it into the L2 magician I'm looking for.