I am not sure if this is because of my really good energy regen modules for T2 but I found a bug that allows you to use afterburners and still regen energy. I activate my afterburners, keep them on then activate then deactivate my aegis system (it’s green). Sometimes it takes awhile for my energy to slow down but I always end up gaining energy while I am using my afterburners. I should probably say that I am using the Fox-M, a federation fighter.
Fighters make a lot of energy.
I run around with three Command modules always on in my Deimos 2 (with a discount) and can still afterburn a reasonable amount.
Working as intended. Federation advantages are speed and energy regen. You should have more energy regeneration then other fighters because speed is pretty much all you have as federation.
You should check out the energy regen and the energy use of your afterburner.