For steam release - Do not FULLY remove portal chambers - Instead make them a perk for racial warfare.

Instead consider them as a perk for racial holding warfare - which is seriously lacking in rewards/perks/incentives (or so I've heard). So racial holdings (cities only) would have connected portal chambers. Portal chambers deactivate during an active challenge (or better yet just have them outside the city walls, where enemy forces can just destroy them).

Thinking about my time in DF realistically - I'm not going to spend 40+ minutes running to the other side of the map like the good old days, for the CHANCE of action.