First result: Card was "sublimated" to backing paper, unsure of how the print came out at this moment Pressure was heavy.
Will try less time, but not looking hopeful.
Update: After cleaning it up a bit, it did sublimate, however isn't really usable due to the plastic melting to both sides of the paper.
Second result: Time reduced to 33 seconds, pressure set to medium/heavy. Lot less paper buildup, however the card still melted a bit and warped worse than the first attempt. This was an actual card with a magstripe, and the top and bottom layers actually separated a bit.
I've got one more test print left to go, however I would not sell these cards to a customer. These are the same cards that are used in hotels for door locks, and a lot of casinos and such use them as employee id tags, really really thin plastic.
Third result: Heat reduced to 370, 33 seconds, pressure same. The backing paper pulled right off, however the card was still really malleable, I tried to straighten it out and cool it off in my hand by blowing on it. It came out a little bit warped. The front paper came off easier, however I still had to drench it in water for a little while and scrape it off. Since I'm scraping the actual card and the print isn't relieving, I would say it is in fact sublimated. However, there's also a slight odor given off, which may be a potential health hazard.
Here's some photos of the results, but I'd say stick to a product designed for sublimation (030 poly coated aluminum or fiberglass reinforced plastics/FRP), plastic this thin wasn't meant for the heat and duration.
Photo 1: First attempt with minor cleanup, photo's a little bit out of focus, but it's also distorted from the layer of paper on top.
Photo 2: First attempt with a better cleanup
Photo 3: Third attempt with cleanup about equivalent to photo 2.