A few points worth considering:

1. Qt4 is dead upstream, EOL since last year
2. It doesn't seem to have active maintenance: last version was out 3 years ago
3. There's a RC version never pushed from last year
4. The author has said "The development of LB has been frozen for good since 0.4.8." (although he hopes to resume development)[1]
5. The author is still active in forums etc.

I won't give a final yes or no, but IMO it wouldn't make sense to push unmaintained software in Tumbleweed, at least until the above situation resolves.

[1] https://sourceforge.net/p/luckybackup/discussion/873563/thread/89cfb82f/

Fair enough, I'm aware that development is currently frozen, and the package is pseudo-unmaintained. Nevertheless, it's an excellent piece of software that seems to work perfectly, with no bugs that I've encountered.