I use this free plug in from astute graphics, you can set the increments as you please and use the arrow keys saves trips to preferences too Keyboard Increment Using the arrow keys on a keyboard to move, finely position and step an artwork object(s) is a common task. Normally buried in Illustrator's extensive Preference UI,DirectPrefs makes the distance setting for this operation immediately available. With three user-definable presets for each document unit of measurement (millimetres, inches, pixels, etc.), you can switch regularly to ensure that each object is easily positioned DirectPrefs - Astute Graphics You have to make a free account, download their installer and select DirectPrefs
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