While Animal hybrids are a finicky and fickle thing to achieve, plant hybrids are much easier (though with layers of complexity).
Assuming the gametes of both parents have properly reduced during meiosis, hybrid offspring end up with a midway point in the amount of chromosomes. Pair a hexaploid with a diploid, and you get a tetraploid. Pair a tetraploid with a diploid and you get a triploid. Even numbers tend to be fertile and fruitful, odd numbers tend to be sterile at lower levels, sometimes fertile at higher levels. Depending on the chromosomal math you’ll sometimes get aneuploids which are near a standard ploidy level, but with an extra chromosome or two (not enough to bring it up to the next level). When unreduced gametes are added into the mix, the offspring get higher ploidy levels than normal, sometimes higher than either parent.
This kinda stuff can be seen with strawberries. Fragaria x vescana is a cross between a tetraploid F. vesca and the octaploid F. x ananassa… with that ploidic math, hexaploids were expected, but it seems the octaploid parents didn’t reduce the gametes while the tetraploids did. So, unreduced octaploid gametes with reduced diploid gametes from the tetraploid parent makes for a decaploid plant. F. x vescana are decaploid hybrids. Meanwhile, “Florika x moschata” is more standard, with properly reduced gametes… a decaploid parent with a hexaploid parent, and we ended up with another octaploid strawberry.
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Back to Diospyros…
I grew Jackalberry a few years back. It was slow-growing in a pot. It died when I put it in the ground. Not sure what went wrong, though I later became aware that it likes acidic soil (if I remember correctly), though I don’t know if that was the issue.