Nope, play dumb and avoid them. A polite hi if you see them should be the extent of your interactions.
By telling them you know about their op you make it known that you know about growing, which in tweaker brain = this guy grows let’s break into his house. You also make yourself a suspect if anything goes down at their place. If my neighbor warned me about my vent then I got ripped a couple weeks later they’d be at the top of my suspect list.
Lastly, as I’m sure you know, tweakers = trouble and any involvement with them brings you into their tornado of methdom. Fuck that!