I installed the halos before the tint but it's probably not a big deal to do it after. I just didn't want to mess with them after the paint and tint was done, so I couldn't possibly scratch the finish. Scratching the raw plastic is bad enough but it won't show after paint and clear.
Remember that AAC deals with a lot of different cars. You probably got someone clueless on the phone who only knew the general answer.
If you're going inside, I'd encourage you to get a couple strips of white LEDs and slap them in the reverse area. I'm really happy with mine. Mounting is a pain (I used lots of double-sided 3M tape). If I ever go in again I'll drill a set of tiny holes and use fishing line to secure them even better.