The problem is that there is no Qt package available for Tumbleweed, so in addition to building Jami itself, I also need to provide a package for Qt. I tried building it using the Qt 6.8.x development packages, which are available natively in the OS and that was not without difficulties. In any case I was able to start the Jami GUI app, but it crashed with a segmentation fault after displaying the login dialog. I don’t have any experience or knowledge of the Jami codebase to identify the cause or fix the issues.
So in general the drawback is that there is no version available for the latest Leap and Tumbleweed. As a result, openSUSE or SLES are not suitable for Jami. The only workaround is to enable the snap repository, install snapd, and then use snap packages. This seems strange to me because Ubuntu-derived distros (where Snap is promoted) are already well-supported by Jami.
P.S. I used Fedora before, and its update cycle is very similar to the rolling release model I experienced with Tumbleweed.