Cat introductions - can't follow usual schedule

I recently adopted a new cat who's a special case. She's 2 years old and was a feral kitten who got scooped up by a TNR program. She probably would have been released back outside, but she had advanced stage tooth reabsorption, had all of her teeth removed, and was taken in by a shelter. I adopted her after she spent more than a year with a foster. She isn't hostile, but she usually hides from humans. She eats and plays happily when I'm out of the room. Reportedly she LOVES other cats and never had a problem with a cat introduction at her foster.

My resident cat is a 4 year old velcro cat who is very timid and has no known record of interacting with other cats. She's had supervised visits to new cat's room and hissed a few times, but hasn't tried to approach her. She seemed pretty unbothered during her last couple visits to new cat's room.

I can't follow the usual advice about feeding or playing with them on opposite sides of a door, or most of the other recommended slow introduction steps, so I'm not sure how to proceed. I'm planning to keep bringing resident cat to visit newbie's room, but newbie won't come out of hiding while I'm there, and I want them to directly interact eventually. Any ideas? After a few more calm visits should I just put up a petcam, leave them alone together, and monitor in case I have to intervene?

Both cats are spayed females.