As there's no mod that reduces the power and PD drain of beam lasers I'd suggest picking a mod like sturdy mount L1 and spinning until you get useful effects like thermal shock, the effects (from Inara) are listed below, I've only used thermal shock on pulse lasers so I can't comment on how useful the other two are.
http://inara.cz/galaxy-engineers
POSSIBLE EXPERIMENTAL EFFECTS
Concordant Sequence
A modification that causes weapon strikes to temporarily enhance the regeneration rate of a wingmans shield, at the cost of increased heat generation
Regeneration Sequence
Friend or Foe Beam modulation upgrade. When the beam strikes a wingmans shield its energy is regulated, regenerating the shield instead of damaging it.
Thermal Conduit
Experimental upgrade that increases damage output based on heat level of the firing ship.
Thermal Shock
Articulated focus array designed to spread heat effectively. Strikes to shields and hull impart additional heat into the target.
Thermal Vent
Experimental upgrade that increases heat dissipation when successfully striking a target, at the cost of increased heat generation when missing.