Wow Mangy! You've outdone yourself! I just want to start off saying that the level of quality you've achieved with Yukon is absolutely exceptional! The detailing and theme development are far and above the best I've seen almost any map lately, not to mention your gameplay and balance still thrive!
As far as what can improve, I've got a few thoughts. Considering that you're now beginning to reach league play, which makes me so happy for you (can't wait to hear how teams react too ^^), there are just a few things extra that may need to be considered. Also there's some slight glitches to correct.
1) All of the metal in rc2a (CP signs, CPs, etc) glows white.
2) Slight leak by the 2nd point. Located on the lowest level facing towards the wall which has the entrance to the new route. If you're coming from middle by the lower route, it's on the right branch. (I had taken a screenie, but I'm lazy, soz!)
3) Sniper Angles. They've increased literally fivefold since the last version with the addition of your new route. I'm not going to claim that they'll be overpowered or even at all effective in comp, but from the looks of what shots I could cleanly make just on my walkthrough, it will likely be a complaint of high-level teams, especially those who face teams with rapetastic snipers. I don't know if it needs to/can be addressed, but I hope it's not a problem!
4) Clipping felt perfect! You did an amazing job creating the forms of the walls and I think you'll get no real complaints here. ^_^
<3 mate and great work! Good luck!