I had a minimum connection on YHZ-YUL-USA a while back where my CRA was swapped for a DH4, resulting in a slower flight. I think I had about 40 minutes by the time I got off. I got to the TB gate before boarding began.

They won't close the door until T-15 if they're still waiting for anyone, so that means it took you 40 minutes? TBH that sounds a little more FOTSG than FF.

I'm not saying it's easy if you don't have NEXUS or don't know what you're doing, but 55 is easily enough time for me to visit the TB MLL.