Ah ok, they already have a built-in hand-wavey mechanic to explain it. That's handy. Extrapolation from their inability to think creatively and only mimic, it seems like that would indeed set up for physical mimicry too. But that would probably get old fast, since it would have to be at the expense of gaining stuff naturally with levels. You'd either have to be trained everything you want to know, or have the DM set up encouters that makes sense for picking it up eventually. Maybe fun for the first couple levels, but just unnecessary tedium as it goes on.

Certainly makes more sense fun-wise to retcon the scope of the curse to a more limited handicap. Something that fits the scope of a single hardship slot.