No. The overflow would still be above the waterline. Just not as far above as it is now.
I wish I could but I have a canopy that prevents me from coming over the back of the tank.
It's easy to cut a canopy and in this case, it's a far better idea to do so. The system can work how it is but the peace of mind from a Herbie is 100% worth the effort here (and it's silent as well). You'll regret not doing it, I promise you.