I expect some difficulty in deciding who qualifies, however.  There is clearly an enormous spectrum all the way from "submits the odd drive-by fix for typos every few years" to "is lead maintainer of a project used by millions".  I don't really have any bright ideas regarding how to figure out where to draw the line.

Like many, I sit somewhere in the middle.  I've made mostly small contributions to well-known projects and various Linux distributions, larger contributions to lesser known projects, and maintain some more obscure projects[*] - but do I deserve a discount?  TBH I'd prefer to see that money going towards self-employed developers who work full-time on FOSS and rely on donations to survive, since it's a lot harder to make a living that way (although projects such as GitCoin are looking increasingly like a promising way to change that).  So please do not consider this a request for a discount - at least, not unless you're desperate to find people to give it to ;-)

[*] In the unlikely event anyone's curious: https://www.openhub.net/people/rankings?query=adam+spiers