This would be tough to control the degassing of CO2. At least with the internal/corner mount you will have some options (ie, stand pipes)

This will also cast a shadow in the tank due to the distance it protrudes into the tank.

Comparing this to the CPR, the CPR only sticks out 1.5 - 2" into the tank and has a high flow rate(300 gph model CS50, this is their smallest one). Also the flow in opening drop is about 1" and the back box is sealable.