It sounds like a good idea but it does reinforce my belief that KL has a natural RH environment of around 69%. That is why the KL is recharging your Bovedas. If the KL kept the environment at 65% like the Bovedas then they would not be releasing moisture into the air for the Bovedas to absorb. That doesn't mean it's not a good idea. It does give a long life to the Bovedas. I would think that if you had too much KL then the Bovedas would not be able to absorb fast enough and the RH would creep up. I'm just guessing at this.
You may be correct, as I don't consider myself an expert.
But my thought is that KL doesn't have a fixed point... It just moves to an equilibrium with its environment.
My environment is 65. When I spray the KL it is briefly higher. Say 70. It releases that moisture because it's now more wet than its surroundings. Eventually it gets back down to 65 as it fills the bovedas, and they keep it at 65. I have enough bovedas to absorb as fast as it releases, and good circulation, so my rh doesn't spike.
I think what the KL is doing for me is providing a simple way to charge my bovedas without rotating them in/out. It also provides a nice bit of surface area to release rh to level out spikes from opening and closing the door.
For your setup, you have your environment dialed in at 69, and you occasionally add water keep it that way.
But, maybe not. I'm guessing too.