If you're quite crafty, I
think you can do it with the Files to Include filters on the Media Views.
Make a smartlist that:
1. Pre-loads any variables needed.
2. Always returns ALL files in your Library (doesn't filter anything, audio, video, images, or otherwise).
Then, you can use
that smartlist as a Files to Include filter (Playlist Is Any Utilities\Preload Variables) on your Audio, Images, Video, and other top-level views. Since the smartlist always returns everything, its actual effect on the files displayed will be nil. However, it will execute every time you open any of your Views (because the children of the top-level ones, generally anyway, inherit from the top-level ones).
If you sometimes start up directly to Theater View, or use Media Network features, you'll need to add the same rule to the top levels of those systems as well.
I've never tried this. I think MrC
does it with some of his crazy systems, though I can't confirm. The only problem I can see, and this could be an issue in some cases, is that it would re-save those variables every time you opened any View. This could be a performance problem if they're complex, and could mess up the use-cases for the Variables if you intend to use them to do or track something later.
That's why a command line utility would be better, because you could just script it to always run just after you launch MC. But I haven't done it.