Normally I just mix up fresh stuff as I've got so damn much of it.
To replenish you add x mL of replenisher counted up from whatever you've processed, I've got that part fine.
So when I mix up 1 litre of fresh dev, dividing down the amounts I had noted after measuring the bottles, it goes something like this.
Start with ~700 mL, add some part A, mix, add some part B, mix, add some part C, mix.
Now that comes out to be about ~768 mL iirc or so.
Then it's watered up to 1 litre, and then you add the starter.
Now is my replenisher the 1 litre amount sans starter, or the ~768 mL amount.
I've been using the 1 litre amount sans starter as replenisher over the last few rolls, following the Kodak instructions on how much mL per type of film, size, and length etc.
Should I be using the ~768 mL amount as replenisher? I don't think it is, seems illogical, but I wanted to make sure.