[Question] Charity to help people get US stimulus payments?

It seems like once the big coronavirus bill passes, the stimulus payments might result in an interesting one-time opportunity for effective altruism. Apparently, anyone who didn’t file a tax return last year would need to file a return to get the money. A charity that helps people file might be a highly leveraged opportunity for financial help? For example, if you can spend $60 to help someone get a $1200 check then that’s pretty good leverage.

This seems similar to what mRelief does, but probably a better fit for tax preparers. Does anyone know anything?

(On the other hand, I suppose any tax preparer could do this for profit? Hmm.)