Currently in Creo/ProE Toolkit we have model modification Pre/Post event notification such as PRO_FEATURE_CREATE_PRE and PRO_FEATURE_CREATE_POST etc. That's good for Creo Toolkit based application to implement specific tasks respectively in Pre/Post function callback. However in some cases if we set a status in Pre function callback and then reset the original status in the post funcation callback and if user select cancel in model modification dialig then the post function callback will never get called. In this case expose model modification cancel event notification such as PRO_FEATURE_CREATE_CANCEL will be very helpful.
If it goes further to provide an API to check whether Creo is currently in model edit (creation/modification) or waiting for user action that will be great.