> 3) Doing nothing, and using some external program
>    or clunky chunk of shell.
My choice 3 solution.

> I took up the challenge of how to hack this up in ksh.
Just to improve my code a bit and make PS1 look better.

Install jq (for uri encoding support):

    pkg_add jq

Add these lines to your $ENV file:

    OSC7='\[\e]7;file://\h/$(print -nr -- "$PWD" | jq -jRs @uri)\e\\\]'
    PS1='$OSC7\h:$PWD\$ '

Tested on openbsd release 7.8, amd64, ksh.