Whether they are proficiency upgrades (which would be great, any reason to stay the same MERC is great for the player, the meta-game, and the spectator!) or just buffing up a bit, some abilities could use some shine, rather than just polish.
Notably weak are the turrets. Most deployables really. They are too fragile in a sense. I was thinking since everyone has a set of tools now, why not make shooting turrets disable them (30 seconds, or until repaired?), and force them to be dismantled? The same could be done for health stations and the like. I say if everyone gets a set of pliers, lets make more things to tear apart and put together.
This type of semi-permanent battlefield control could be key to allowing other items, like the Heartbeat Sensor, and Third-Eye-Cam to be made stronger tools.