Hello! Psychometry wouldn't work in the OFF world at large (at least for now, he may regain this power later), but he'd be able to try it out in Dodo house; overall, the items there feel quite new! It'd give him the sense that this furniture is frequently rotated and replaced as it gets damaged, like replacing broken down gym equipment. He'd feel general emotions of fondness and protectiveness, which seem to be from the house itself. Otherwise, yes, he might get a sense from communal equipment that someone has drank from this coffee cup before.

In the ON world, it's a little less straightforward: objects are theoretically code, so he might not get a sense that they're real at all. The exception is if he tries to use this ability on anything related to Choices, or that's glitching out -- he won't be able to make out the memories associated with them, but they'll be a bit of a sensory overload, like there might be something there but it's under a wave of static, and it'll probably give him a killer migraine!

Hope that helps!