This page contains my idea for extending Total Commander's functionality which (I hope) will be implemented someday.

There is the possibility to handle in TC thumbnails created via IV or XV but there is no info about how does it happen. What is the current priority of thumbnails loading? As I understand it follows Thumbnails options page and there is no chance to have IV associated to the other files' extensions as XV is.

It would be very nice to have the additional settings set to make it possible. Think about processing speed! In my PC, Imagine lister plugin is the quickest one but it doesn't handle many image formats. Little bit slower IrfanView is but has the same issue as already mentioned plugin.

Nice solution would be to make using both IV and XV at the same time possible. It would be even nicer to specify your own priority for thumbnails loading.

PS1. Even UniversalViewer does not split this two image viewers...

PS2. An external solution could be lister plugin which would work as an interface between TC and other apps/plugs.