"more than confident" is a correct and usable phrase in written English. You can use it to emphasize that you have an especially high level of confidence in something. For example: "I am more than confident that we can reach our sales goals this year.".
Now, he seems more than confident.
We're more than confident going into the playoffs".
For now, though, Hamm seems more than confident that he will be ready to compete.
That's why you practice hard and test yourself and make sure you're ready, and I'm more than confident in that.
He's more confused than confident now.
"At this stage we are more hopeful than confident of his availability".
The result is that the scientists are now much more than 99% confident that the detection was real.
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia