Thanks for pointing this out - here's the link, for anyone interested:
https://github.com/jarun/nnn/wiki/Basic-use-cases#configure-...
https://github.com/jarun/nnn/wiki/Basic-use-cases#configure-...
No utility can support cd-on-quit out of the box because a spawned process can't send the $PWD to the parent directly when it quits. It needs tweaks in your shell's rc file. nnn also needs the same instrumentation.