@orange Well I'm not sure this applies, because ProTools does load with the previous state of each instance, be it on or off.
While in other DAWs, all instances get initialised with the pref file, be it on or off...
So the default value seems to have no effect on this.
UserPresetHandler.isInternalPresetLoad() might help to decide if it's a DAW state that is restored or not... But a pre/post load callback is for preset loading, so if this applies to instance restoration I don't know, I have to experiment... Maybe it's a matter of creating a flag that authorises or not the loading of the pref file, hopping this won't interfere when first inserting the plugin on a track.