Free roaming your chin

We acquired our chin with her at about 5 years of age from a home that wasn’t abusive but just didn’t maybe know as much about chins as they should have. I don’t believe she ever spent time outside of her large cage previously and kind of was just alone in her room unless they happened to be in there spending time with her.

Since being with us we have acclimated her more to being around us, doesn’t try to run when we pet her and seems calm when we hold her. We bought a play pen for her to be able to extend the space she can run around outside of her cage because we’re in an old studio apartment but she does okay but the obsessively starts trying to climb or jump out. She does know she’s not supposed to do certain things (like tear down the cage, or climb straight up it) because she used to try but no longer does even though they worked before lol. We really want her to have more space to run around and be as free as she can.

What do you guys do to help your chin free roam when you’re around? I don’t think I’d ever feel totally safe letting her have completely run of the house but I do feel there must be a solution to have her have more space! Right now besides her playpen attached to her cage the only other safe space with have for her is the bathroom which she does appreciate but is hard because we sit in here with her and it’s not as easy to set up (move everything out, catch her in her cage which is ok but ik it stresses her out).

Thanks!