I don't consider them contraband and have no criticism of the idea in and of itself. I do, however, take issue with people who teach that way and imply that those who don't are somehow teaching a lesser art or are deficient in their knowledge of the forms.My sabumnim is somewhat dismissive of the idea. He says that's what hapkido is for.
<shrugs> I am fond of form applications but because of their seemingly "contraband" status in KKW-land, I have confined my extensions upon Korean forms to the Chang Hon set.