No, it is not available in every Krita. My issue is always to remember which versions of Krita can use it and which can’t.
Unfortunately, I don’t have any other ideas where you could apply leverage to get Krita back on track and make it usable again in terms of the comic manager.
Although…
Are you willing to import the Buli Commander plugin into Krita in the hope of at least bypassing Dolphin for displaying the complete file system structure?
Buli Commander is a full-fledged file manager for Krita, built like the good old Midnight Commander. It is integrated into Krita and allows you to preview your KRA files in thumbnails of your specified size, which of course also applies to all other image formats registered in your operating system.
It can be downloaded from this post, where I offer a patched version that makes it compatible with current versions of Krita again, and it is described in detail in this thread, but the link provided there does not lead to a working version, so download the patched version from my cloud.
If you want to patch it yourself, you can find the code and instructions here.
But that only helps to see/access it from Krita again, it won’t speed things up.
Michelist