Preview speedup

When external preview scripts are used to generate previews of images and other more complex files, some larger files cause a noticeable delay for even the most simple text files. going into a directory with one large image and a simple text file below it and then selecting the text file will delay the text preview. I had one preview for archives that simply listed the contents as text. An archive that is 100Mb large will effectively break the entire preview chain because it will block the generation of other file previews for about like 10 seconds. (Some archive formats need to be read completely to display anything). With the preload option enabled this is even more relevant. There are some solutions that can be added to external preview scripts, like skipping larger files. But that wont allow the actual preview that may still be desired even for larger files. And on slower hardware even a 3MB image preview may cause a noticeable delay. So how should we address this? Or should we just ignore it since its not the core functionality? I am considering a solution that simply uses multiple preview generators with a priority for files around the cursor. That would speed up the preloading of preview data in general and fix this bug as a side effect. Thoughts?