Does that mean he has better vision and precognition than when he was using EMS?
Nope. Rinnegan doesn't do any of that.
How does one again a "better" precog?
The way the sharingan precog works is you see an "image" the your opponents next move before it happens. Better precog would be you being able to "see" further, say your opponent just starts to move, but you can already see their entire sequence of moves and counter it:
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