Is there a way to set the transform origin for the RMX Tuner and RMX Scaler plugins? For example, when scaling the lowercase g, the descender shifts down, while the x-height shifts upward. Fontlab appears to have this option, curious if Glyphs does also?
Glyphs does. But I guess you really want to know if RMX does, I suppose. I believe RMX assumes the baseline, which makes sense.
In any event, do not expect it to give you a finished glyph already, it is just a very good first step. You will have to do your own alterations anyway.
I though of this possibility a while ago but could not think of a typical use case. If you want to tune several glyphs with the same settings then you can select them and the Tuner will be applied to all at the same time.
Sometimes I have one line in the edit tab that contains only the glyphs I want to change (using Tuner or Scaler), and below this a sample text that is a mixture of the to-be-changed and other glyphs, so that I can visually judge the right amount of adjustment.
Multi-glyph tuning seems fine for quick testing; where if you need to undo after applying the filter it would not revert all changed glyphs at once; unless you enter each glyph and click the undo; or revert to the last saved file version.