Not really. a) It's amazing Russia went from just out of feudalism to as industrial as it did. b) If there even was a mistake, it is probably that more demand

Not really. a) It's amazing Russia went from just out of feudalism to as industrial as it did. b) If there even was a mistake, it is probably that more demand and nicely flexible demand (as the consumer economy can provide) would have helped. But that's not about free trade per se. Pretty sure West-East trade was already pretty limited from both sides, and I don't think there were many intra-USSR limitations to trade. For example, the border between Russia and Ukraine has caused many economic issues in the years since.