Zcash NU7 mainnet activation height is set at block 3,543,405, which, at the current block production speed, is estimated to be around November 5. If you still have coins in the old Sprout pool, treat this as a hard deadline. After NU7, all v4 transactions will be invalid, and transfers from Sprout can only use v4. Any coins still in Sprout at the moment of activation will be permanently unspendable. If you want to move them, make sure to do so before activation. Other changes: block time will be reduced from 75 seconds to 25 seconds, and the 3 confirmations required by exchanges will shrink from nearly 4 minutes to just over 1 minute. For each block, 60% of transaction fees will be temporarily removed from circulation and returned to miners starting around February 2031, with the halving schedule remaining unchanged. Additionally, limits will be added for shielded operations both per pool and across the entire network. The height was proposed by Sean Bowe in a PR on October 20 and has already been approved by two developers. However, as of this afternoon, the deployment spec for ZIP 259 still lists it as pending, and node software will need to include this height for it to take effect.