I think finding new ways to push these boundaries in the name of science and health, is just fine. If humans can evolve out of asthma or even cancer, it would be worth it. I think as long as we explore the issues that come with the experiments, we should be fine.
No, human experimentation should not be expanded in the interest of forcibly evolving the human race, because it is inhumane to forcibly experiment on people. Humans would have to make unfair decisions about which people are the most important. They need to experiment on animals and other things that are not abusive of humans.
I really don't think it's all going to be that easy. Just because you twiddle the bits on a few genes here and there, it doesn't mean that you're committing evolution. A quick modification only repairs or enhances one individual. Actual evolution is still something that takes a long time to happen.
There have already been experiments to support the forcible evolution of the human race, and that was called Eugenics. It was the basis of the Nazi belief in Aryan superiority as well as the belief system of those who founded the Educational Testing Service here in the United States. This is a disastrous belief system because the people who want to do this are simply trying to replicate themselves and a society that benefits themselves, at a cost to everyone else. It is a supreme form of selfishness tempered by extreme egocentrism.
Human experimentation should not be expanded in the interest of forcibly evolving the human race. I think that it would be wrong to do human experimentation for any reason. We should not have to be treated like guinea pigs in a lab somewhere. I think this would be wrong and not right.