Thanks. I managed to install it in iFile, and it seems to work fine. One exception (the same as the other day): If I run Cydia, the actual carrier name is displayed and not whatever customization is set in Zeppelin. A new feature or some bug? Nothing critical, though.
One other thing that might cause issues in the future (or not, if I ignore it?): Right now, Cydia displays that 2.0.1-1-1 is the installed version of Zeppelin (at the top, by the icon; if I scroll down, under Installed Package section, it says 2.0.1-151). Also, 2.0.1-1-1 is displayed under Upgrades (definitely not touching this one). If I use AppInfo, it shows the correct version (2.0.1-151). Maybe it's because the package was installed previously from a repo, and it picked that info somehow as this time it was installed manually from a local file. I suppose it should clear up once the repo version is higher than -151.
EDIT: After a (rather lengthy, ~3 minutes) reboot, the custom Zeppelin logo is shown as before, whereas custom "carrier text" (that new setting) is displayed when in Cydia. Guess it's a bug then. (The custom text isn't displayed system-wide if I set logo to "none".)
Also, Safari and Mail crash at once (that's why I rebooted). Not sure what this is related to, guess there'll be news during the day if it's related to those other major updates from today.