Tried it anyway. Put it in a no-name wood I got for 6 bucks, so if it fell or I flung it on purpose, no loss.
But there was no real problem on a touring bike. First lit it and set out just tooling around. No worse than chewing gum. Smoke not an issue, as it cleared right away. Embers and ash, no issue.
Then turned to a low traffic blacktop just outside of town. No issues. Then up to the interstate.
No problem with flying embers or anything as I imagined. But on the interstate, once it got burning too hot, there was no way to cool it down. The air behind the windscreen, though attracted toward the windscreen, is moving. The pipe is never in still air. Always drafting pretty good.
Though nothing dangerous developed at all, tobacco was too hot to taste good. Not enjoyable.
Risky? We all draw our own lines. But I also ride without a helmet where the law permits, and I ride 5 mph over the speed limit fairly routinely, which it doesn't permit. I am such a madman daredevil. I'm sure several 1-percenters are trembling in their cuts right now, afraid I might join their club and raise the bar of bad-assed-ness higher than they're comfortable with.
LOL