FCP X re-rendering noise correction plug-in any time I make a change

I have started to use the Neat Video plug-in in FCP X to remove noise, which is caused by the low light conditions I am having to shoot live bands in. (Hopefully two Super 35mm sensor cameras, which will replace a 1/3" sensor camera, are going to solve this in the next few weeks).

My Projects are simple and short. Each includes only one band song, 10 minutes long max. The rendering for this plug-in takes a long time (approximately 75 minutes for a 5 minute song), and you have to wait for rendering to occur before doing anything else in FCP X (Neat Video Support calls it a "temporal filter").

The problem is this:
Everything works fine if I apply Neat Video last, just before I export.

So, I usually: Edit video->process audio in Pro Tools->correct color->remove noise->Export.

However, if I do anything after applying Neat Video, and then try to export, I find FCP X completely re-renders Neat Video. I say it re-renders because, when I export, the time is around 75 minutes rather than the usual 5 minutes.............I assume this means FCP X is completely re-rendering Neat Video.

I have discussed this with Neat Video tech support at great length (they provide outstanding support, BTW) and they tell me there is no reason Neat Video needs to be re-rendered, once it has been applied, unless I choose to apply the plug-in again. They also say that the plug-in does not control the decision to render, this is controlled by FCP X. I have spent enough time talking with them that I am convinced they are not just passing the buck.

Here is one example of what will trigger this:
After applying and rendering the Neat Video plug-in and just before I started to export, I realized I had forgotten to pan the audio (FYI, I export the original audio, process in Pro Tools, then import multi-mono audio back into FCP X. It must be panned in FCP X). I panned the audio, a 15 second job, tried exporting........and it took 75 minutes to export.

This kind of issue only happens if I am using the plug-in.

Why would FCP X decide to re-render the noise correction if anything is done after the first rendering?
How do I stop it?