I'm giving up... crqpoffs and its brother also didn't work wonders. The bitrate went up... but even at the maximum of -12 it still didn't reach a detail retention level I liked.
And aq-mode 3 didn't work out for me as well... I went as far as setting aq-strength from 1 to 5, ultimately with a crf of 33 (~6000kbps) but... no.
If someone is out for a challenge... grab Aladdin and try to bring it down to a 5000kbps encoding without totally smeared red backgrounds.
You'll start to hate the ladies at the window at 0:07:19 - 00:07:24.
Personally I'll go on with zones... It'll take hours but it will work in the end.