That HEL MD has some quite bad setbacks doe. One of them is the laser power - it still needs a quite long time for the laser-beam to heat the warhead/fuel to get it blown. That means, the "radar" early warning system needs to get the projectile really soon after fire. Also just limits the systems use only to long-range shots and cant engage alone a battery (8-12 artillery units normally) at standard fire missions. (you have to get the same amount of these vehicles to the spot). Also, its wont stop the initial shoots - in order to get the projectiles detected, you have to aether get lucky to point whyte the radar at right spot from the very first shot (or surveillance of the entire sky), or locate the approximate battery position trough acoustic means (there are vehicles/systems for this too). You can start a hunt after the battery soon after, hit it whyte counter-artillery fire. But agile few shoots artillery systems will be on its way at most of the time ... its practically just an defensive mil-base protection system, needing the 24-7 surveillance of the whole corridor to get cost effective in realz ... and mostly just for flat regions, where "over the hill" shooting is not possible. (but probably not so effective at mortar fire distance of an small group - thats the most probable scenario to the US army anywhere it is). .... For drones it might be good, but not sure if modern mobile systems arent enough for those anyway ...
On the other hand, having the HEMMT in few variations would be nice ...