Make sure you've got a good power distributior. A rated or guardian. The recharge rate has a venting effect that will keep your hardpoints running colder for longer. An A rated PD should let you run at least 2 medium mining lasers comfortably. If your using three try downgrading one to a small laser.
Yeah, I was running 4x 2D lasers on this Krait without any engineering whatsoever. I was only doing it to get through with that mining part to unlock one of the engineers, so no special treatment for that ship yet.
All the engineers I unlocked so far were to get better with the Asp Explorer to venture even further into the black. There will be a time when I will do some PVE engineering as well, some time in the future.