One thing I’d love to see is a good pipeline for converting developers with a casual interest in Zcash into full-time Zcash builders. This means having amazing documentation, libraries, and infrastructure that makes it possible to build cool things on top of Zcash in just a few minutes or a few hours. The impact of ZSAs will be massively amplified if building them is a great experience, hence my ZSA usability challenge.
When a prospective developer is interested in building on Zcash, the more frustrating confusions, long sync times, or complicated protocol details that they have to wade through to get their thing working, the less likely they are to they succeed and stay in our community. So I think this is really important, and it will take a lot of collaboration to do right, since developer-usability considerations should bubble up from documentation, library design, to the protocol design itself, and public infrastructure for developers to use is important too. We also need to consider the usability experience of developers as we make backwards-incompatible changes to the core protocol.
Zashi and the Keystone integration have made Zcash so much more usable for end-users and we’re about to accelerate Zcash core development by deprecating zcashd. If we can attract developers to build their own (hopefully profitable!) products on top of Zcash too, that has the potential to bring in whole new audiences of prospective end-users to keep the surge flowing.
(These are my personal opinions, not with my ZF board member hat on.)