Very interesting, first time hearing this about seed cannibalization so that a few may survive! Do other Gourd crops like melons & Squash do the same? Of course it depends on how unripe you pick it. I just rememebr how @UnicornEmily picked a Zuccinni x Spagehtti Squash hybrid Green (After 2 weeks on vine) and it managed to ripen fully off vine after a long time.
I’ve seen this, I thought it was dependent on the genetics of the particular variety, perhaps the stress determines how much the hermaphrodite flowers trait gets expressed? Surely there are some cultivars that no mater how much stress you give them, simply refuse to make hermaphrodite flowers.
I think this right here was what you meant?
It appears they can also be bisexual which is different from Hermaphrodite flowers. I think this would be a useful trait for those times when you only have female flowers but no males & vice versa. Would it make controlled crosses more difficult tho?
Time to determine what ripe is! Without breaking the watermelon. Some varieites actually snap open when slightly touched to let you know it’s ripe (Which kind of defeats the point 
). Those Golden Varieites are easy, but is every golden variety like this? What about the moon & stars cultivar, is it ripe when it gets the “Moon & Stars” on it’s skin or no? I’ve also heard both tendrils have to be withered brown, the skin a bit dull & if grown on soil, the belly spot yellow with even dark sugar spots.
I’ve noticed the the sound trick is pointless, I once picked a very hallow sounding watermelon it was unripe. Is the peduncle a good trait to determine ripeness? I know some muskmelons have the peduncle slip off when ripe, does watermelon do that too? is there a problem picking it over-ripe?