A few years ago someone made a macrobar by folding the membrane of a Cherry G86 keyboard in half. They had to do it carefully so the traces didn't break, but they ended up with a working keyboard. You might be able to do something similar, perhaps. https://deskthority.net/viewtopic.php?p=233187&sid=76253b9b87174d7a5bfc67ebe650a1d7#p233187