It was normal in those times for conquistadors and related people to oive in Santo Domingo or elsewhere in the current DR for many years before they went to other areas of Latin America. For example, Bartolomé de las Casas lived in Santo Domingo for a while, officiated his first mass in La Vega and lived in Puerto Plata for years before heading to Mexico. Francisco Pizarro lived in Santo Domingo for many years before going to South America and becoming the conqueror of Peru.
Hernan Cortez immigrated first to Santo Domingo and lived in Azua too when it was a costal town. In total he lived in modern DR for some 8 years if I'm correct before heading to Cuba and then to Mexico, where he became the conqueror of that place. It's basically a given, especially with him, that many people today in the places they lived and beyond are direct descendants and most don't know it. Cortez is said to have been an above average handsome manthat impressed even men because of his commanding presence. He was what today is known as a mujeriego, went as far as sleeping with the married wife of others. In fact, the reason he had to postpone the year of his immigration from Spain to Santo Domingo was due to an injury he suffered when the husband of a woman he was wife arrived at his home inexpectedly and he hurt himself throwing himself out a second floor window to avoid getting caught by the man. If that was in Spain where blue eyes, tall stature, white skin, sharp facial features, etc are not rare; imagine once he was in this side of the world where homogeneity was the norm and men were often shorter, brown shade, dark eyes, black hair, etc. The guy had to standout everywhere he went and women of all type had to notice that. The fact that the guy had no control over his sexual appeal meant that he especially had to leave mestizo and white kids by the boat load (no pun intended) everywhere he settled. In Cuba he got in trouble with the governor Diego Velazquez because the wife of the governor seem to have a inclination towards Cortez and she was Spanish, it was not as if what she saw and experienced from the guy had to be new to her. Now imagine the indigenous women who until seeing him had never before seen all those features beyond myths.
Bottom line, living in Santo Domingo for even a decade before heading somewhere else in the Americas or back to Spain was normal. That's also a long time for anyone to do nothing. I'm sure that if DNA is extracted from their remains, especially Hernan Cortezwhich are in a tomb in a church in Mexico City, and they analize the DNA of many Dominicans, a larger number than most expect would most likely be related to him, bynow spanning all colors and features, and all social classes.
The samething had to happen when black guys began to appear in sizable quatities all over the Americas, because just how the indigenous never saw things like white skins or blonde hair or green eyes;, they also had not seen things like black skins or kinky hair. Being different, that too had to impress many.