Show and hide overlay

I want to create some hidden panel, when player is connected to server and show it if a player press some button.
Now it's working by creating an ui, when player press button, but with some lags. So i need to create UI once, when player is connected to server, and just show and hide it, without using AddUI and DestroyUI.
How to do it?

 

And so, in my understanding, I cann't do this now. I need to change the UI on the client side, and the oxide now only allows to add and destroy the elements of the interface. Without the possibility of change.
Is it possible to add to the next versions of Oxide, the ability to change the interface elements already sent to the client?
(Change opacity for example, could help for me.)

 

All you have is AddUI & DestroyUI respectively.
Oxide has just a wrapper over Rust CUI and doesn't manages it, thus in order to update UI element you must destroy it and draw again.