On the fence, leaning on the no tag side.

It is a case of better-safe-than-sorry. Even though I disagree to some extent with statements suggesting that reputable airlines don't lose luggage (baggage handling is done by independent crews. Post COVID had been major mayhem. Google "Pearson airport problems"). Yes, they'll most likely be able to deliver it to you within a few days in the event of a missed connection.

So it seems to boil down to spending 40$ so I know 2 minutes earlier that my bike is about to show up at the oversize luggage door, vs wondering.

For the record, my handbag was once forcibly stolen from me, by 2 teens, daylight, busy street, plain sight, lots of witnesses. Pushed to the ground, brief struggle. Nobody cares. Part of the world where "rich white people" are a resource for the locals. Tags wouldn't have made a difference. Part of the world I was familiar with and had good friends. Stuff happens. Otherwise life sold be boring...

So, yeah, leaning on the no tag side of the fence.