Beforehand I was able to zoom in/out using the 2 finger scroll gesture on my trackpad. A recent update either yesterday or today has broken this.
On the RobloxPlayer client I am able to zoom in/out using the pinch to zoom gesture. I would assume that Roblox is currently trying to unify these behaviours for Studio, but even pinch to zoom does not work on Studio when doing Play Solo.
The only way I would be able to get around this is plugging in a mouse.
The behavior while playtesting in Mac Studio has been updated to exactly match the behavior in Mac Client. However Studio doesn’t support the pinch-to-zoom gesture yet, so until we do you’ll have to use the I/O keys to zoom during playtesting with a trackpad.