It might make more sense to call them “patronage” certificates, or similar. Because the certificates can really be bought or sold by patrons who value them for any reason, not just impact. Rather, there is some subset of the funders who are focused on impact and value the certificates on that basis. Basically, impact-oriented patrons. This name is easier to understand because we are familiar with people wanting & receiving credit for being the patron of some art, or as a funder on Patreon.
It might make more sense to call them “patronage” certificates, or similar. Because the certificates can really be bought or sold by patrons who value them for any reason, not just impact. Rather, there is some subset of the funders who are focused on impact and value the certificates on that basis. Basically, impact-oriented patrons. This name is easier to understand because we are familiar with people wanting & receiving credit for being the patron of some art, or as a funder on Patreon.