My former agency had a Federal Labs L-6 launcher back in the day. In those days, only sergeants and OIC's were smart enough or trustworthy enough to be allowed such sexy tools as the launcher or the 9mm carbine. I'm not sure what we would have done if the sergeant or OIC were on leave or on another call and both weapons were needed. I'm glad we got past those days in the nineties.
I suspect I'm the only sergeant who threw the L-6 in the trunk or actually had it deployed on a call. Accuracy became an issue that ended the program though that likely was because of poor maintenance of the weapon.
Unfortunately, I don't have much at all to contribute on current technology, but I'd avoid the supervisor only philosophy on assigning the weapon. While issuing gear to a supervisor with the intention it will be handed off on scene does make theoretical sense, you're going to have to reinforce it through doctrine and/or training. Giving the cool guy gear to the guy who wants to be cool (and is willing to go to training) will probably get the gear on scene sooner and with a motivated operator than giving it to the sergeant. Unless, of course, the sergeant is like me back when I was relevant and had some purpose.