Created attachment 39210 [details]
Deadlock

First I thought that it would suffice to use Settings.class for kitsTracker but
it would probably further deadlock on IC$ConvertingItem.

Don't touch settings from your kit's constructor. You should implement
Settings.Initializer and register this implementation with
Settings.addInitializer and set the default values for your settings in
S.I.updateSettingsMap. It is safe to call S.addInitializer (and even S.reset)
during the kit's construction as it does not synchronize on Settings.class object.

I know the old editor settings infrastructure has its quirks and with hardly any
documentation it's not easy to guess how things should be done. I'll add this as
a usecase to Settings' javadoc.

fixed.