I really like this org. When I play board games, I play faster when I know I'm allowed to take moves back. Similarly I can imagine that if I know I can get money back if I am in hardship, I can imagine I might give more.
Conceivably in a better world, many people might have "charity accounts" where the difference between some baseline and the invested money goes to charity but you can pull it out at any time. Many people wouldn't and so orgs would get the interest as donations.
Consider hardcore volunteers as well; some EAs unironically volunteer 30 or 40 hours a week while working part-time to support themselves. I did that for 3.5H years or so.
This is something we'd like to expand to, but it's much harder to define "EA volunteer" than "donor to effective charities". Once donor assistance is running smoothly, we'll likely give volunteer assistance a try.