Re: '90s Called...
Beat me to it (and - spookily - with a very similar name).
Yes, Chinook was the internal name I believe for their high end drive that had two actuators - one at either end of the platter. A bit of a nightmare really as with it being a totally different head stack doing a similar job I think there might have been some tracking challenges.
Add that to the much higher costs due to 2x head-stacks, and I guess we can see why it never took off.
I like this idea of splitting the stack though. Not sure why nobody did this before. (Maybe they did..?)