I used plug on my Honda Odyssey PAX RFT tire before. My tire back then only have 10k miles & I used the tire 'till it worn out at 35k. To my surprise, the plug hold really well plus the van is much more heavier than a car.
So, in my experience...it's ok to use plug on an RFT tires. Patching is more expensive because tires needs to be removed.