Scaled UPM change doesn't scale Smart Component and Master values

Bug Report: After scaled UPM change, Smart Component range values were not changed per the UPM scale change. The Smart Component range values were set as multiples of UPM values as suggested in Glyphs literature. The stored Smart Component values of instances were scaled but the range was not, so the resultant smart components are off by the amount of scale that was not applied to the Smart Component Range values. Manually changing the Smart Component range values seems to return the Smart Components to the original relative size in the font.

Similarly, the values of the font Masters, for weight, width and custom, were not scaled after UPM scale change. Although I didn’t have any instances at the time, I assume that this will result in some incorrect application of the Master values to underlying font graphics that has now been scaled to different value ranges. I assume that manually changing the Master values per the UPM scale change could solve this issue.

So in further testing, even though the Smart Component ranges are not UPM scaled, it appears that the Smart Component object values are also not UPM scaled so the results are correct and consistent as intended. However, since the Smart Component ranges and object values were originally set to match the UPM values of the objects, once the UPM is scaled these values now do not match the current changed UPM values of the objects, which can be confusing and hard to keep track of. From the way that I am using the program with smart objects, it would be better if the Smart Component ranges and object values were also scaled so they were consistent with the new UPM, which is what the Glyphs literature suggests. I understand that perhaps some implementations may use 0 to 100 percent as a range rather than 0 to 100 UPM, which might mean there is no right answer for this depending on how someone set up the original Smart Component ranges. Given that the smart component range and object values are not UPM scaled, my only option if I want the ranges and values to match the UPM, is to change the ranges in the Smart Components, and then to go through the entire font and change the values of every instance of the Smart Components in the file, which is a few hours of work and something for me to consider.

Can you:

  1. Describe your exact steps.
  2. Send an affected .glyphs file to support (at) (this website without www), please. I will have a look.

And what is your reason for changing the UPM?