If you don't want a smoke buddy.... Try
vaping unflavored at work, if you must
vape in the bathroom.
Also um, I would check your local HR ordinances as far as what Disciplinary action #1 looks like.
I have developed a different system to handle work (snus) and it's working out pretty well.
I would not enjoy
vaping in even a single use bathroom, honestly let alone a shared one. Also, if I was doing that, I just have a hunch I'd be thinking about when next I could vape in the bathroom, even with a really high nic setup.
I like no one knowing I vape, it's kind of fun. Also, zoning works for me. I have vaped 0 times at work, and I like it that way.
Best of luck with the smoke buddy. Your coworker sounds horrid, but they totally exist. Horrid coworkers, etc.
Anna