The humanitarian concern about the ongoing war of aggression (where Russia is using these bombs on Ukrainian civilians) outweighs the concern on this matter... Where Ukraine is furthermore using them on their own soil...

It's only a war crime if it comes from the Moscow Oblast region of Russia. Otherwise it's an unfortunate but necessary defense strategy.

Considering that Ukraine is considering using them on their own territory which is already filled with more landmines than you'll be able to get rid of in a lifetime, I think that's their decision to make. They will be the ones dealing with the consequences of this, it's not as if they invaded someone else's country and used cluster muntitions on civilians of that country like, say, for example.....Russia...

What the hell

Both Russia and Ukraine have been using Soviet-era cluster munitions since early in the war. The US made versions have a lower failure rate so it's preferable that Ukraine use those instead.