Sprite Texture first rendering issue

I combined sprite text with LOD to make it appears when camera is close, here is the demo:

However, when the model with 2K spriteTexts begins to initialize, the first rendering is always time-consuming. So I want to know how to improve it. Is there anyway to merge them together, while the individual distance is calculated to each text

First, the storage cost of high resolution texture maps can easily exceed the available texture memory. The dificulty to create planar parameterizations official website further worsens this problrm since memory can be wasted by unused space in the texture maps or by disorted areas.