Hi, I just thought of an idea for how to implement custom villager trades on console editions.
Custom Trades would only be available to create in Creative mode, but could be used in survival, or adv mode.
They would work like this:
1. Spawn a villager.
2. Enter its trading screen.
3. Drag items from your inventory over to the Required to Trade slot, and to the top bar where the villager offers trades.
Example, if you wanted to make a villager sell an iron sword for 20 wood, you'd drag the 20 wood to the required for trade slot,
and put the iron sword in the top slot bar.
This would be useful for
1. Adventure maps
2. Obtaining multiple enchanted items easily
Hopefully I'm not copying someones idea.
I think this would be an awesome addition in the next big update, and is reasonable because the trading ui already has your inventory on it.
Comment if you want me to reword anything to explain it easier. I'm not very active on here, so it might take me a few days to reply.