The cards I've tried works fine in PnP mode, I wonder if it's a case of those cards of your being configured for their own RT jumperless invention rather than "industry standard" PNP jumperless?
But then again, what are the odds your bunch of cards were that and my two were not..
(Edit: and since you could see it at the address you set in the PNP registers I guess that wasn't it after all)
Either way, feels like an auto folder driver could be good, which can handle configuring their RT jumperless mode.
Alternatively, ugly hacks in ISA_BIOS to specifically detect RTL8019 and use their RT initiation key rather than the standard PNP one.
Why oh why with the custom Realtek jumperless crap... is my big question here

