That'll work.
The tether, the way you have it, is very clean looking, but the distances between your saddle attachment and your footloop length will not be very adjustable. Not a problem if they are the perfect length. The relationship between the length of the tethers affects the reach of your arms and your leg steps. You want nice even leg steps, you don't want one over reaching the other.
I'm not a real fan of the double handled ascenders. One, because they can come off the rope. I find a single handled ascender used with two hands better. One hand on the top of the ascender protecting the entry point of the rope. And secondly because most guys I see using them pull quite a bit. You shouldn't be pulling with your arms on a single rope climbing system. You want your legs to do the work. So a short upward reach with your arms, basically just moving the upper ascender, and maintaining body position is all you are doing with your upper body.
As long as the Croll is attached to your harness and the upper utility biner advances it consistently when it is attached to your suspenders, I can't see there being a concern about overloading the Croll.
Have you been using this setup? If so, how does it work for you? That's kind of the bottom line.
Dave