@Van Beal, if you have seen a chamois in the past it is far more likely you saw Bailey's deceased companion Julie. She died earlier this year. She was the one who was more likely to be somewhere visible. Bailey has always liked his privacy where as she was more chill and came closer to people. If you get a chance to see him before he passes enjoy it because I believe Toronto is the last AZA zoo to house them. Other zoos in the US might but they will be the smaller zoos or private facilities.
You have poor timing or bad luck with the wombats. I have never not seen a wombat and I visit maybe once or twice a year. Now their exhibit mate Annie the echidna, I haven't seen her once since Edge of the Night closed other than in photos and videos. Not sure if this will help but I usually end up on that side of the zoo mid morning to noon. I like to hit the health unit when someone might be in for a check up. But since I am there at that time might help to gage when you can catch the wombats. Though someone who visits more might be able to help you dial it in better.