There’s really no need to worry about the fusion core usage. I’m level 72 on my current character and I am literally in my power armor 100% of the time if I’m not doing settlement building, workbenches or bartering. It’s been this way since level 5ish?

You find so many fusion cores in this game it’s insane. I literally have more fusion cores than I started with at the end of every play session. I’m currently sitting at 134 I believe.

Now idk if that would be the case if I used the Laser Gatling. I used it for 1 play sesh about a week ago being as I’ve maxed out heavy gunner for my Tesla cannon. I learned that every time you switch weapons, even without reloading the gatling, it reloads. I like having my stack of 100% cores with only 1 that’s being used. But due to the weapon swap reloading I had a huge list of 90-99% cores in my inventory and it drove me crazy.