@garethtdavies, I have a tremendous amount of respect for you. I consider you to be a leader in the Zcash community, and you have helped so many people here in this forum by lending your expertise to answer questions (including my own questions on several occasions). But would respectfully (and vehemently) oppose any proposal to extend the Founders Reward. (And I would welcome debating this in the context of a ZIP.)
If a significant portion of the community rallies around a proposal to extend the Founders Reward and ZcashCo follows, I think the best way to combat this (for those that oppose any extension of the Founders Reward) is to “Friendly Fork” chain split as soon as possible, call the new coin something that doesn’t infringe on the Zcash trademark (let’s just call it FriendlyForkCoin, or FFC, for now), and siphon off ALL of the remaining unvested original Founders Reward on the new chain to a nonprofit FFC Foundation devoted exclusively to funding the open source development of FFC.