Here is my proposal for the future devfund.
It is similar to the bicameral proposal by @joshs as it can be viewed as a bicameral system, but the key difference is that coinholders will not be directly voting on specific grants. Instead, every year there shall be a coinholder vote as to whether to send 20% of block rewards to the Zcash Community Fund (a multisig wallet controlled by the Zcash Council), or to store the 20% in a lockbox. If the coinholders vote for the former then all accumulated funds in the lockbox and 20% of block rewards for one year will be sent to the Zcash Community Fund. If the coinholders vote to stop funding the Zcash Community Fund then the 20% shall immediately begin to flow into a lockbox, and there shall be held a vote every month until a majority of coinholders vote to start funding the Zcash Community Fund again. Ideally, I think the coinholders should be able to partially fund the Zcash Community Fund, but that is probably too complicated to implement.
There are two reasons for this separation of powers between the coinholders and the Zcash Council. Firstly, since they have different roles, they are less likely to develop close relationships, which makes them more likely to act as a check on each other. Secondly, when decision making power is shared among a large group of people, each individual has little incentive to invest lots of time and effort to acquire the information needed to make the best possible decision as it is unlikely to change the outcome of an election. Aside from big whales, this problem applies to coinholder voting. This suggests that coinholder voting is more appropriate for fewer and more high-level decisions that require less information.
Lastly, I think 2 of the 5 ZCG members should be elected by coinholder vote. I think indirect representation of coinholders will give us a different and valuable kind of committee members.