Hmmm. Incinerate. You mean, like medical waste?
Over 600,000 abortions are performed in the United States every year, according to the CDC. Not all, or even most, of those are usable for medical research. In fact, even you admit that only "some" is donated to research and development. What happens to the rest?
Hauled away to where? What happens to it when it gets there? Do you know? Do you care enough to know, or are you happier comforting yourself with, "I'm sure it's all okay"?
The truth is, how those remains are treated depends on which state you're in. Some states, typically those which are more pro-life, have laws requiring cremation and burial. Many states have little to no regulation, and those regulations that do exist mandate that the remains be treated as "pathological waste", as it's phrased in the California statutes. That would include incineration. New Mexico law requires either incineration or burial, quite specifically. Texas law specifies a choice of disposal options: incineration, grinding up the remains to discharge into a sewage system, burial, stem disinfection followed by burial, moist disinfection followed by depositing in a landfill, chlorine disinfection and maceration followed by depositing in a landfill, or any process that renders the remains unrecognizable followed by depositing in a landfill.
Tell me again that pro-aborts don't call fetal remains "medical waste", because it's written in plain English in multiple state laws.