Overload tends to be a terrible idea, turning your weapon from the most reliable indestructible thing in the galaxy [you honestly believe the Golden Throne would have lasted that long if it wasn't a giant gold-plated pile of lasguns? Of course not] into "sarge, it jammed and accidentally all the ammo again, can I get another one?"… Unless you absolutely can't harm the target otherwise, or you're facing an attrition-death a few rounds away from two less damage every hit, stay away from overload. The costs seriously outweigh the benefits.
Overcharge isn't really worth it unless you're doubling your damage with it [that is to say, targets that take 1 on a 10 rather than expending RF to take that 1, and so now take 2] or you've got a lot of spare packs, or its integral or something. Its decent enough so long as you're not worrying about remaining shots.
However, for all its near-uselessness on so many things across the galaxy, there's a reason Lasguns are everywhere. They're energy efficient, and can get charged off damn-near anything. Its pretty safe to assume even the Astartes motocross has at least a port compatible with las-packs somewhere so you can charge like one an hour or something. I doubt a Chimera doesn't have a handful too. Lasgun Charge Packs are the USB of the Imperium: We field them because nothing else keeps going quite like them.
Really, if you so much as empty a full clip with your lasgun in any given fight and you did NOT use overcharge or overload? Its because you're firing at something the munitorum didn't think you'd have to deal with on that mission. That's the entire POINT of lasguns as a whole: We put them everywhere because they're easy to make and make logistics easier. "too much ammo" is their entire raison d'ètre.
Like a guy in carapace, or a space marine or Carnifex. Just keep firing though; the artillery's on the way.