Sounds cool. If you hate the health implications, don't use it. It's 2022; nobody who smokes is laboring under the belief that it's good for them.
The emote needs to LOOP though. We have so many emotes in this game that should loop but don't. Like /read for example. Why do I read for 5 seconds and then immediately put the book away? It should loop. Imagine if we get like, a pipe smoking emote similar to Yotsuyu's movements, but you only smoke for 4 seconds and then you put it away. It'd be so bad lmao.
Anyway, I'm sure we'll get it soon. Maybe SE will partner with Marlboro for a Malboro themed cigarette adventure, and if you purchase a pack and send in the receipt you'll get a /smoke emote!