Also TBH I doubt the real life value of many of those currencies. In the end we need to convert the donation into real money (which is by the way a tax problem also, since its hard to trace for financial governance and therefore considered as "money laundering" possibility which would be very bad for the foundation), so if we receive a donation on day x, and 2 weeks later the value has gone south, the donator has wasted his money, and we gain nothing.
Unfortunately crypto currencies are highly speculative, and so are IMHO not the right vehicle for donating to a foundation that has long-term goals.
BR