I have an addon that I would like to add a field to the user schema through a GenericSetup profile. I had hoped to do this with a userschema.xml file but this completely wipes out any TTW added fields or others installed with a profile. I just want to append, not override. As far as I can tell it doesn't respect a purge=False attribute in the element or anything. Is there a different XML config file I should use?
I could probably figure out a way to do this programmatically but it seems like something that should be doable with xml configs.