How to increase memory efficiency with App Designer and huge amount of generated data?

I created a quite simple UIFigure. It contains just a few buttons and two UIAxes. The mlapp contains a formula which calculates some data and the Axes are used to compare different iterations of the result. For simliicty here, lets assume that I want to compare different sets of rand(1,300000) - so, kind of huge data here. These has to be in the axes in-detail, because I want to zoom in and spot the differences. Sadly, the app reacts slow, so zoom via mouse input is not very comfortable. Internally, I store the data as propperties (Access = private) to process it further. That makes up to 3 copies of the data within the app: one in each axes and in the defined variables from the private properties. Is there a better way to store/process the data to make the behaviour of the mlapp a bit smoother? (Reduce the redundancy as well as a better way to use the created data within different parts of the UI.)

Edit: for a better understanding I attached a stripped app which explains the current data storage/handling