Is there any specific reason that the =sidebearing does not autoupdate by default?
Would it be possible to have something like =[sidebearing] (or some other way of indicating it) that would force it to always autoupdate when the value in the specified glyph changes?
The problem is that running the update automatically breaks the undo for that glyph and I haven’t found a solution for this yet. So I disabled it for now.