I do think a development fund should be aiming for a set period time (not indefinitely) for several reasons, such as re-evaluating if the funds are being used effectively. However, I don’t really see why the re-evaluating period (ending blockheight) should have to coincide with the block halving schedule.
I purposely chose a set period of 11 total years of funding in my proposal to make Zcash “good” (ie, fast, scalable, adopted, etc.) and to avoid complacency. I did some calculations, based on the suggestion of 9% for 7 more years:
- Founder Reward of 10% of total supply = 2.1M ZEC
- Development only plan of 9% over 7 years = 641,650 ZEC
- Total ZEC allocated 13.05%
- Total monetary supply unchanged
I think that an additional 3.05% of the total supply of Zcash for development is a reasonable amount that the community could support. Feel free to use these numbers in a proposal if you want, I have withdrawn mine due to implementation challenges.