Can’t find that script. I need to reduce many glyphs’ side bearing at once.
Are you sure you need percentage? Because that usually messes things up. Because flat glyphs (like i and n will be changed much more than round or diagonal shapes (like o or v). And glyphs with negative side bearings are going the other way.
So I would recommend to use the Transform filter > Metrics. Check the Relative box and add/reduce spacing.
If you really know what you are doing: mekkablue scripts > Spacing > Change Metrics by Percentage.
If you want to reduce all of them, and perhaps even similarly, do not use percentages. With percentages, you will reduce some sidebearings a lot, some a tiny little bit, some not at all, and some will increase.
We discussed this in the forum a few times. I have never seen a case where a percentage in metrics would have made sense.
Thank you all. I will use it with caution.