Greetings Alessandro,

I don't think 20 degrees will be a problem. I have done it with 15 and I had a dead center plate solving. Just keep in mind NOT to hit "done". Just stop the process,switch from west to east and the opposite (based on which direction you begin) and start the process again. You may need to do the process several times based on how much error you've got. But be patient. Wish you the best.

George.

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