Speeding up the preview override?

Hi, I have a C# node (not visual studio) with custom preview overridden.
What the component does is iterative computations and updating the preview every step.
I noticed that when I turn off the preview, the FPS is over 5, but if I turn it on, it is somewhere around 3.
The objects are trimmed surfaces. Every step, the control points of the surfaces are updated, and the trimmed edges are rebuilt. So replacing them with meshes and only updating vertices do not seem like an option.

Is there a magic-ish technique to dramatically speed up the preview?
I’m, already running the preview and the actual computation parallelly. But when the computation part is finished, the previous preview is still going on. So the preview part needs to be substantially improved.