Disagree that such a change could be included in either of those two Network Upgrades, for reasons of business continuity for our partners (wallets, exchanges, OpenBazaar, Purse, Shapeshift, etc. etc. etc.) and project management (our current team is completely allocated for pulling off Overwinter and Sapling successfully and we can’t add to or change the plan at this stage).
It could definitely be done in a subsequent Network Upgrade, which could activate as few as three months after Sapling activates if we get started soon deciding on it.