Hello,
I’ve played a few games of this mode and thought I’d share my view.
I think the game mode is a fun and exciting new thing, I like it and I think the map is great.
However I do believe that mercs like sky and arty should be banned.
2 reasons for this: the general concept of the game mode is similar to a CS type of game mode and the map is open for the most part.
Airstrikes and arty strikes create a somewhat huge advantage. Nades can be dodged, Airstrikes which where planted on the one side of the train and hit the other side can’t. I know it sounds newbie to say this but they’re an unfair advantage.
Also as with games like CS, for this particular mode, you should have limited ammo (as in not get more from arty and sky) so you choose your engagements well and don’t spam spray.
Now in an opposite view I’ll add that I think this game shouldn’t be compared to CS so my previous point is sort of invalid, but since this is a prototype map and mode, I think that certain point can be taken into consideration and experimented with.
Also a suggestion:
The last part of DOME map can be used for this mode, it’s both wide and poses a cool challenge to capture either site 
These are my humble two cents and any opinions are welcome 
Keep on playing dirty! <3