I have face some performance issue on opening / coming back to Dashboard after game has finished, not while in-game which you can see your dashboard by clicking an arrow on the top left of the screen.
After the game has ended, of course there will be a button to close that game and back to the dashboard. And in my case, after clicking that button and the game has been closed, it's take a long time to open the dashboard, even I have to wait 2 minutes some times, but average is about 30 ~ 50 seconds.
My technical specification is

Device type : Laptop ( I know, maybe this is the issue )

CPU : Intel Core i7 2630QM
GPU : nVIDIA Geforce GT 540M ( onboard, well It's expected as I play on a laptop )
HDD : 1TB (it is necessary ?)
LCD : 1366 x 768 60Hz
OS : Windows 10 64 Bit

and for the settings on DotA 2

I Use Advanced Settings for both resolutions and rendering

Resolution :
- 16 : 9
- 1280 x 720 ( 60Hz )
- Borderless Window ( because when use fullscreen, it's even worse, average is 1 minute and sometimes my dota just freeze waiting to be terminated )

Rendering ( this is the only checked options )
- High Quality Water
- Texture Quality [ Med ]
- Effects Quality [ High ]
- Shadow Quality [ Off ]
- Game Screen Render Quality [ 100%]
- Max FPS Allowed [ 60 ] (it can't even hit 50 :'( even all the switch are off and use Low / Off settings, so I use 100% Quality and High Effect for better result with same AVG FPS )

Steam Launch Console [ -high -nod3d9ex -antiaddiction_test -console +sv_cheats 1 ]
- previously I use [ -gl ] but after my windows updated, some OpenGL related stuff is broken, even I can't play some of my game ( Ori And The Blind Forest because the OpenGL break, and I'm in the middle of game developing, so I can't just re install the windows before I finish my project )
- oh and my driver is always up to date, but since the windows update that break OpenGL my driver seems to be affected in weird case.

So ... is there a possibility of improvements to this ? or is it because my OpenGL break ? Well In-game as I mention above, not very pleasant but plenty with AVG FPS 30 and highest is 46 ~ 47 ( it's sad, I know ) but I can play comfortly ( as long as the net connection doesn't going crazy ). But after the game finish, when I wan to queue next game, I have to wait up to 2 mins just waiting the dashboard "appearing" and if I click something while this is happen, well you guessed it, it's freeze and sometimes goes into Not Responding.

Thank you.