The Church looks at motives to achieve ends. If the motive is to help people deal with or overcome disabilities through genetic engineering, then the end is a good. Other motives to use genetic engineering to create radical changes solely for, say, increasing the military effectiveness of a soldier, can be bad. Example, whoever invented body armor for knights saw their creation fall by the wayside when arrows were used. Or, the country with the first atomic bomb was viewed as a threat by others until they could develop their own. Human beings, all of us, have a good side and a bad side. Or some have too much money and time that without sound ethical principles to guide them, might order the creation of just about anything.
What if an enemy made a breakthrough in genetic engineering that would increase the survivability of their soldiers on the battlefield to double of what is normal? That would be viewed as a threat. I’ve seen the numbers of soldiers who were unable to fight due to disease and certain types of non-life threatening injuries during World War II (and some conflicts after). If they could be ‘patched up’ using genetic engineering in the field, the enemy would be a more potent combat force.