The new rules make mixing and matching drugs very dangerous. a double dose of Kamikaze, for instance, deals a whopping 18 points of stun damage. Kamikaze and jazz come in at a not insignificant 17 stun, while K + cram will still floor most people with 13 stun.
"Oh great Fueldrop" you cry (except you in the back there. I've got my eye on you...) "How is this even remotely useful? There are toxins that do comparable damage and are cheaper. Why would we want to consider hitting our foes with two doses of combat drugs if purpose designed poisons are eminently more practical."
See, the thing is that you don't have to hit your targets with two doses. Many foes cannot afford initiative enhancing cyberware, and as a result will apply the first dose to themselves before entering the fight. With a low risk of addiction (relatively speaking), low cost and long duration Cram is the kind of drug that you can reasonably expect your enemies to use if they cannot afford to get augmented but still need that edge in a fight. A gas grenade full of Jazz into a group of individuals already on cram hits them for a healthy 12 stun without the risk of friendly fire to allies or hostages (Tell any juicers on the team to wear a gas mask).
"But Fueldrop" you exclaim (You in the back again! Come on, put some effort in here!) "Isn't this incredibly circumstantial and impractical?"
Yes it is. In all honesty, a gas grenade full of a combat drug such as jazz is not as much a weapon as a way of getting the whole group drugged up with a single action. if you happen to be flooring any nearby enemies in the process, then . Also, this tactic has a good chance of backfiring HARD if your opponents aren't already on drugs.
"Thank you for the dumbest idea I've ever heard." you conclude (oh what, NOW you join in? Fine, I give up.)