@jamescowens and I were talking about that.

"The idea is that the staking UTXO would be evaluated by the code against the formula I put out on steem yesterday, and if the UTXO is larger than a network wide efficiency setting would indicate is optimal, the stake UTXO output would automatically be split into 2 or more pieces to reduce the UTXO size below the value required for the given efficiency. Essentially, over time, this would achieve automatic UTXO optimization for staking. ... Normally UTXOs from stakes go back to the same address from whence they came. What @quezacoatl is getting at is some people might have significant UTXO value stuck in change addresses, and those will stake. Under normal circumstances, the stake output will go back to the change address if it came from a change address, which might be less desirable than a non-change address..."

must have: opt-in flag in .conf
nice to have: setting the minimum value of UTXO size

"So... conf file entries (or command line arguments) of EnableStakeUTXOOptimization=0 or 1
MinimumStakeUTXOValueForSplit=x and if someone puts less than 800, code uses 800.
We could probably also create a checkbox in the UI to set EnableStakeUTXOOptimization"

800 is the rounded value that gives a stake efficiency of 95% at a difficulty of 1.0.