Do you think scientists should use techniques like PGD to identify genes linked with more complex traits, such as height and obesity?

Yes

Explanation:

Preimplantation genetic testing can be described as the technique used in identification of genetic defects in embryos which was created through in vitro fertilization (IVF) before pregnancy. Preimplantation genetic diagnosis (PGD) can be explained further as when one or both genetic parents has a known genetic abnormality and testing is performed on the embryo in determining if it also carries a genetic abnormality.

In this case, this method can also be adopted to find out some other issues about the unborn child, such as knowing the height, and maybe the embryo will be obese or not.