I have seen a map of what RK was intended to be and i have also heard that the zones exist and are just disabled. There are Maps for sale in the shops for these zones.
Such as
Plains of Salt
The Reck
The Spur
Three Craters
Bay of Rome
To name just a few
How about fixing what ever was wrong with these RK zones and putting them in.
Plains of Salt is between PW and GTC which does lend itself to Dust Brigade and Borgs.
New RK zones would be something nice to explore.