At least in Kubuntu 18.04: cbz files can not be browsed using the right arrow key (although it works for cbr files). Note: Krusader is aware of cbz and cbr files since 2016 (a commit from Davide: https://cgit.kde.org/krusader.git/commit/?id=f3d4e86a4ae0ce022bf095522c17208023208708).
There's a proposed solution in https://phabricator.kde.org/D23549
@Toni Can this be closed?
This bug report can be closed.