This is nice but in the reality, the gpu need a proper space to one another to freely flow the air on both side, in this kind of setup the gpu will supper the high temperature.. Just saying..
Nope the fans on front and back will keep airflow fine. I have 100's of this type and heat is not the issue. Making sure it's in a clean enviroment and making sure the fans are running is the main thing you need to be worried about