I think the whole benzo+opiate myth is completely overstated. Yeah, you'll die if you take 8mg xanax, then do a shot thats big enough to make you nod on it's own. But say 2 bags of a certain stamp gets you good, and 4-5 make you nod. Taking just the 2 bags, and a few bars won't do anything. As long as you're not taking enough opiates to nod, then taking benzos you'll be golden.
I feel like the same thing with benzo+alcohol applies too. People freak out about the combo, but unless you're downing 40mg of bars, and chugging a bottle of whiskey, you're not going to die. I've had 8-12 drinks, and a few bars with no GABA drug tolerance before, and was perfectly fine, just a little more sedated.
As long as you arent taking enough to make you sleep/nod you'll be fine. I personally think the whole combo warning is a legal failsafe, so when some dumbass drinks a bottle of whiskey in a night, because he took 5 bars, and it lowered his inhibitions, then the company doesnt get sued.