I originally made this as a patch for my Lunar Fallout Overhaul, but liked it so much I decided to strip out that dependency and make a version balanced for vanilla players. So here you go:

Compacted and esl flagged. Fallout 4.esm and the Creation Club Tesla Cannon are the only requirements.

Tesla Cannon
Base Damage: 60
Ammo Type: Plasma Cartridge (from fusion cell)
Base ammo count: 5
It now has a charge mechanic with a 3 second charge up to full power (sadly no indicator).
It now has a reload animation! Though this is just the missile launcher animation, it still greatly improves the feel of the weapon and helps balance it.

Receivers have been streamlined to just 4 upgrades. Each increases Damage. The minimum damage per shot (when firing before the 3 second charge up) is increased. Ammo capacity is raised 5 per upgrade (up to 20).

The two fire modes are unchanged.

Barrels have been adjusted. Higher level barrel upgrades increase the Tesla Cannon explosion effects (moved from receivers).

A custom Legendary effect is added to the weapon that provides +50% damage to Robots, Vertibirds, Turrets and Power Armor. The lore of the weapon is that it was designed to be anti-vehicle. I just kind of went crazy and added all machine foes.

Instance Naming rules tweaked (I changed Jury-Rigged descriptor to Focused as it makes more sense).

NPC who spawns with the Tesla Cannon is provided with some plasma cartridges.

No edits to the quest or extra scripts added as this is supposed to be a unique weapon.