This one is bizarre. I changed the overclocking on my GPU (going down 3%, was getting some mild overheating when running modded FF-Type Zero) and now TFN (and only my TFN install. CE, Plus and basic are unaffected) displays wireframes for environment (character models and interactables are normal). Screenshots do not show this.
Restoring my old setting and removing all overclocking fixes this. Currently testing to see if I can reliably recreate. Change in background programs seems to fix it as well, but simple 'quit and restart' did not at first. Maybe something to do with invested system resources?
I doubt this is anything that is worth more than an "interesting" from Zer0, but if anyone else has seen it in any form, I'd be interested.