Never thought a game could be so hardcoded like that.
It's sad, really sad. I really loved the open world of WD1, but I understand the limitations even though I'm not a programmer myself.
My limit is installing custom maps and messing up with Object Spooner and some callouts that work anywhere.
There's a Chicago map for GTA V currently in the works though, If haven't seen it yet:
https://www.youtube.com/watch?v=ZpChSxuu-ec
I'll make sure to check these videos too, after I finish WD2.