It's worth noting that improving open hand strength will also make you strong in the crimped position but not the other way around
The reason I asked is that when you train open hand you are not weighting the flexor digitorum superficialis. This is the muscle used for a crimp of pinch grip.
I think Dave McLeod does research along some of those principles, maybe worth asking him?
You could try asking around (on here for example) for subjects to set up your own trial, I'm a bit busy at the mo' though, with work
is it just me or has the moon traning diary stopped?