Disclaimer?: Everything written down below is my prsonal opinion, iam not trying to encourage anyone to change game mechanics, these are just my thoughts.
Why dont instead of EnCap reduction, weapons who have that, make them damage en regen(malice beam and hysteria in particular). I’ll try to explain why it’s more appropriate for Energy Draining builds.
Lets say u have Cl and Savagery equipped on your mech, your way of defeating opponent is overheating them. Ok thats crlear.
Energy counterpart of this build would be a mech with malice beam and hysteria. With this build your goal is to drain opponent to 0, thus making him unable to use his weapons(exept for EnFree ones) and vulnerable to bonus damage of En weapons.
The goal of first build(Heat) is to overheat and the Heat cap from these weapons helps in achieving this
The goal of second build(Energy) is to drain to 0, i think that changing stats of these weapons(with EnCap damage) to EnRegen damage suits them better in that regard.
Please feel free to share your opinion.