Question: how to replace EDF ?

Say you have a WAD with an embedded EDF lump in it. And now you want to add/change some definition in this embedded EDF lump by eg adding your own modification EDF file at runtime.

How can this be done?

Seems once a thing definition is loaded, it cannot be changed by a second EDF file that either replaces the thing definition or adds a thingdelta for it. Loading a lump with the same name as the original embedded EDF lump also does not change the original definition.

So far I've only managed to do so by duplicating all the original EDF files together with a wrapper that includes a modification and have it preloaded before the original WAD.

EDIT: Mentioning solution for others: name your second EDF file EDFROOT and it will be automatically loaded.