Hook for altering initial add new/add existing form

I have an inline entity form to add beans to a node. I want to alter the "Add new/Add existing" form.

You can use a simple form alter to make changes to this initial form (the add new/add existing form), however, once you have loaded the inline entity form and hit cancel, the original alter is not run when the initial form is reloaded.

Hook_inline_entity_form_entity_form_alter does not have any effect on these forms. Is there a hook I am missing, or can one be added so this could be possible?