I'm all in favour of signing up as a marrow donor (I'm registered with DKNS myself) but burdening charities with administrative tasks to save yourself money feels a bit... cheap, and you get a lot more for paying for a full genome sequencing or even a 23andme report.
Waystar used to off a free look at a nonprofits 1040's. I believe their are other that offer a free look at this public information.
So many nonprofits are ridiculously overfunded. So many only pay a livable salary to the key founders, usually an husband and wife team.
One day, I want to put together a list of good nonprofits.
I once heard St. Jude Children's hospital has enough funding to last for 20 years, including costs of new technology; if donations were cut off today.
My point is be savvy with donations. There are very good charities out there.
(True story. National parks have one spot in the park available for first admendment speech. In Muir Woods National Monument it was a couple of parking spots. For years this guy used to hand out flyers to tourists who just got off buses.
He had some nonprofit that proposed to save Redwood trees. I looked up the nonprofit, and couldn't find it. Every night he would show up to the local watering hole with a 3" stack of money he woukd count out. I imagine he was making 2-3k a day. Why am I enclosing this? Because I'm tired of charities taking advantage of certain people.)