At the beginning of Ubooquity, I had plans to include this feature.
Then, after writing the first version of the scanner (which periodically polls instead of monitoring the file system), I realized that the check of the files (the part that would be eliminated by the OS hook notification) was extremely fast as it is just a date comparison. Files are not actually read unless they have been modified (in which case a rescan is necessary in any case).

So the gain would very probably be quite small, both in terms of time and CPU resources.
Did you have a specific problem in mind that would be solved by such a mechanism ?

It's already planned. :)

This.

There is already page preloading, but it's not working in all situations and deserves improvement.
It's planned as part of the enhanced online comic reader.

Thanks for sharing !

Seems to be a H2 database bug.
I'll migrate to the latest version of H2 for the next Ubooquity release, that should make this bug disappear.

In the meantime, you can work around this problem by running Ubooquity in any non-root folder (i.e. create a folder on E: and run Ubooquity in it instead of running it directly at the root of your disk).

Took me some time but I added Chnuky Reader as my recommended reader for iPad in the FAQ.