If you load this mod and its two dependencies (stdlib and PickerAtheneum), but nothing else, you will get the error "real number expected got nil" when trying to switch from "Belt Brush Corner Left" to "Belt Brush Corner Right". This is the stacktrace:
31.793 Script @stdlib/stdlib/core.lua:50: real number expected got nil.
stack traceback:
stdlib/stdlib/event/event.lua:419: in function 'raise_event'
PickerBeltTools/scripts/beltbrush.lua:308: in function <PickerBeltTools/scripts/beltbrush.lua:271>
[C]: in function 'pcall'
stdlib/stdlib/event/event.lua:302: in function 'dispatch_event'
stdlib/stdlib/event/event.lua:372: in function <stdlib/stdlib/event/event.lua:336>
Installing/enabling PickerBlueprinter will make the error message go away.