Proposal: for ZIPs proposing consensus changes, require a public persistent feature-gated testnet as a prerequisite for some maturity level.

[nathan-at-least]

Would it be productive and valuable to require that a ZIP may not reach a certain maturity state without the presence of a persistent feature-gated testnet (assuming the ZIP alters consensus rules)?

If this were a requirement of the ZIP process, it would ensure people know early on this will be a necessary step, and as the ZIP matures this would help ensure the testnet exists prior to the community decision time about including the ZIP features into an upcoming upgrade.

OTOH, adding another requirement may inhibit some people from proposing ZIPs. Is there any way we could encourage "pre-testnet" ZIP proposals anyway?

In the status quo, it's often node implementers who set up testnets rather than ZIP authors (although that's changing!) so even with this new testnet process requirement, the labor could still be divided that way. Maybe node dev teams or other developers could proactively "sponsor" early ZIP ideas for which they would contribute to testnet deployments?

[teor2345]

How is this different from the current "Implemented" status?

The requirements are generic so they cover non-node changes. But we've typically taken them to include a testnet deployment for node changes.

zips/zip-0000.rst

Lines 618 to 621 in bf21364

	* Implemented: When a Consensus or Standards ZIP has a working
	reference implementation but before activation on the Zcash network.
	The status MAY indicate which node implementation has implemented
	the ZIP, e.g. "Implemented (zcashd)" or "Implemented (zebra)".

zips/zip-0000.rst

Lines 655 to 662 in bf21364

	A Standards ZIP SHOULD only change status from Proposed to Implemented
	once the Owners provide an associated reference implementation. For
	Consensus ZIPs, an implementation MUST have been merged into at least
	one consensus node codebase (currently zcashd and/or zebra), typically
	in the period after the network upgrade's specification freeze but before
	the implementation audit. If the Owners miss this deadline, the Editors
	or Owners MAY choose to update the Deployment section of the ZIP to
	target another upgrade, at their discretion.