Adjust Kerning Increment in Preferences

Simple: 

I want to be able to adjust the kerning alt + arrow nude kerning level. Currently defaults to +/-20 with no way to change and extendscript is not cursor aware so no way to do it with a script either. Always have to access it via properties / char panel which is not ideal. 

Why:

Figma type engine is a bit different than adobe so microkerning is something I do a lot of right now.