This works?
NEATO! Thanks very much for the tip.

I'd still rather have my Engineer BOFFs doing something more helpful all the time, then have a mostly wasted ability that's useful rarely.

RE: OP topic

I tried telling the cover shield 'you're fired!' and it wasn't happy.

Now, every time I deploy a cover shield in combat it spawns behind me and when I look up I'm promptly nailed to my own shield by the enemy

Are cover shields sentient? Do they have rights?

(This is happening since the first of the March patches).

Mortars are great vs slow moving enemies I.E BORG, Elite Gorn. They do great damage in bursts which is perfect when combined with knockdowns and slows. If you can get mobs to mass to a single point they can be devastating since they use ae damage and can hit for 300s (or more sometimes).

I use mortars against other targets too, but some might be annoyed by the setup that I do. I place a phaser turret in front of my mortars a ways and put mortars behind and in cover if possible. The mobs run up and start shooting the phaser turret and my mortar/s demolish them. I also flank the enemies with my other doffs and myself, tends to wipe most groups out very fast and harmlessly(to my team).

I have also used cover shield on boffs but usually only on maps where there is not a lot of cover and not in restricted places, they are just too inconvenient at times to use. My typical loadout on an Engie Boff is Phaser Turret 1or2 Medical Generator 1or2 Quantum Mortar 3 and either a weapon malfunction or shield recharge.

I just used them for a ground PvP map. Mortars are awesome and they are indirect-firing. I got a few mortars up and the enemy team had a very hard time breaking through my fortifications because stand still for a few seconds and ignore the purple marker = boom.