If you are careful, a sharp mandolin should be able to save time cutting them in half. I don’t think its possible to use a home food processor to get perfect halves. that disc is meant for carrots etc, really hard veg. even if you pulsed the machine once, you would get uneven cuts.
Freeze dry technology is becoming closer and closer to a reality for the home, from what I’ve read maybe 5-10 years for a reasonably priced appliance with a service contract to refill the necessary gasses.