it is easier for the bb to die, so the parents are wasting more energy raising the young compare to fisher+ fisher or peachface+peachface
also
小葵花 can't breed with LB, and i think it is quite dangerous to put cockatiel with lovebirds
I got three hybrid lb bb (mixed with peachface and fischer), luckily all of them are very healthy, they can fly quickly and more smart in interaction with ppl.
on the other hands, 4 lb babies from another pair of fischers, 2 die with legs or vertibate disable and 2 left with one is spray legs also...
somehow I can say.... depends on luck and their parents health more...