After using this new version for some time, I think the interface freezing problem has been solved, even during the indexing process there is no freezing.
Also off topic, I think there is a little logic bug when adding index file categories, because I have to select a specific file of that type to proceed to the next step, which I think is not necessary. For example, when I wanted to add the epub type, I searched for the epub file on my hard drive for a long time before adding it, and I was expecting to see the next prompt box as soon as I filled in the epub string.