From work in the Ethereum community, specifically getting involved in some of the Core Dev work at the lowest levels of infrastructure that impact the entire network, I came up with the outline of a framework for thinking about grants: project time frames, grant sizes, and purpose of the grant. I've put this on the Ethereum Wiki, so it can be edited and extended by anyone.
This is a companion discussion topic for the original entry at https://blog.fission.codes/can-grant-making-be-faster-low-overhead/