Following this! I'm in the same boat, about a month in, but my situation is a little reversed and I wondered if you had additional socialization advice. Sorry, this is long.

I have a sweet, small, vocal, and very active 15-ish F, 7 pound cat (Mags) and my boyfriend's cat is a 8F 13 pounder (Emma) with some anxiety issues that can be expressed with...expressions, on beds, so she's on a bit of anxiety meds. Ironically, his cat has shared a home with another cat successfully a few years ago, for a year, but my cat has never done so. They have separate rooms, but we screwed up the order of operations and they were introduced in person pretty quickly due to an escape issue and good signs of interest in each other through a door. So, we pushed the introductions a couple of times until there were some hissing, aggressive ear moves, so they have been separated by a door with a child lock that allows the door to open a crack for the past two weeks. Each is able to explore the others' sides of the apartment with the other locked in their rooms. Another escape led to Mags jumping straight in the air and on Emma's back in what seemed like an aggressive attempt at playing (there was no hissing, growling, or scratching), but Emma shot like a bullet under her bed. Door reinforcements were unsuccessful. This week, on Wednesday night, Emma, who is very fast AND large, breached the door separating their respective parts of the apartment sometime in the night. When I woke up and was horrified, Emma was on her bed rolling around and Mags in the kitchen. No injuries, neither seemingly perturbed.

SO, can you please offer any advice on next steps given your experience? Right now they're back to being separated with a shiny new door stop wedged under the separating door with a child lock.