SF Pro (and SF UI) doesn't switch between "Text" and "Display"
# Sketch Version 44.1 (41455)

## Summary
It looks like the plugin is no longer dynamically switching to the correct variation of "Text" or "Display" for SF UI or SF Pro, and if I'm using "Text" when I am >20 pt size, then it does nothing.

This plugin is a life-saver, but it'd be great if this issue could be resolved. Thanks!

## Full Description
### If I make a new text object... (all good)
* SF Pro Text (or SF UI Text)
* 16 pt
* Default character spacing 0
... then use the SF Font Fixer plugin, it correctly applies the correct character spacing (-0.38).

### If I make a new text object... (issue!)
* SF Pro Text (or SF UI Text)
* 24 pt
* Default character spacing of 0
... then use the SF Font Fixer plugin, nothing happens.

It should...
1. change my SF Pro Text to SF Pro Display
2. apply the correct character spacing (0.33)