First off, great mod. Bringing elements of tc4 into tc6 while being its own thing has felt amazing to play around with, I'm only sorry I didn't encounter this addon sooner.

Yesterday I played around with the Impulse Cannon for the first time, and I have to say it felt a bit... empty. The name of the mod is Thaumic Augmentation, yet despite allowing you to augment caster's gauntlets heavily, you get just two incompatible options to choose from for the cannon. The fact that the cannon underperforms compared to gauntlets, despite being leagues more expensive, is also notable.

So I brainstormed for a bit and came up with ideas for more augments to make the cannon more customizable and more powerful. I am willing to put in the work to open a pull request for this and code it all myself (though any textures I make will be highly questionable); I'm looking for the green light, advice on how to make my ideas fit in more with the mod, and ideas for more augments.

Conversions:

• Charge Rifle Conversion: Cannon is charged like a bow, slowing movement, firing a single beam on release. Range is proportional to charge time; damage and cooldown time are proportional to the square root of charge time.
• Thermal Accelerator Conversion: Think classic minigun. As the cannon 'heats up', aka the more you fire it, the faster it fires up to a limit. Once it reaches the limit, the player is set on fire every time the cannon fires.
• Crystal Diffuser Conversion: Attaches intact Strange Crystals to the cannon, continuously firing random spreads of impetus beams in a cone in front of the player. Each crystal the conversion is crafted with increases the number of beams, but increases the size of the firing cone and reduces range. (2-5 crystals).

General augments:

• Impetus Charger: By routing impetus through an onboard impetus drainer, impetus can be further charged before release. Increases magic damage by 50%, but halves normal damage.
• Impetus Disrupter: By siphoning a small amount of impetus to an onboard impetus generator and injecting the mundane energy back into the firing system, impetus can be destabilized before release. Increases normal damage by 50%, but halves magic damage.
• Impetus Solidifier: By integrating a void siphon into the cannon's systems, impetus can be partially converted into solid state before release. Doubles impetus drain, but allows the cannon to break blocks and deal heavy knockback.
• Primordial Purifier: By reacting impetus energy with a complete primordial pearl, it can be infused with devastating primordial energy. Magic and normal damage is reduced to 20%, but 40% of the original damage amount is also dealt as non-magic, armor-ignoring damage (non-magic so entities that are resistant to magic damage are no longer resistant to this damage). Impetus drain is doubled.
• Augment Mount: Allows an experience, frenzy, or biome modifier to be attached to the cannon's greater focus and operate at reduced effect. Focus power increases damage, vis discount reduces impetus consumption, cast speed reduces cooldowns or improves tickrate for continuous fire types. Only one augment mount can be attached.
• Underclocking Unit: Halves impetus drain, but damage is reduced by 10%
• Overclocking Unit: Doubles impetus drain, but damage is increased by 25%
• Gyroscopic Adjuster: Introduces aim assist, moving the beam slightly off crosshair if it would otherwise just miss an entity. (extra raytraces, basically)
• Hyperion Amplifier: Triples impetus drain. When firing, all impetus in the cannon is used at once (or over 5 ticks for continuous fire types), but damage is increased proportionately.
• Auxiliary Cell: Quintuples impetus capacity.

I'm going to make a more detailed response with my thoughts on your suggestions, but in general - the impulse cannon unfortunately didn't get as much put into it (along with other impetus things) as it should have. Making it better would be very much appreciated.

It's worth noting that there are plans to deprecate and then remove the crafting grid approach for adding augments and switch to a dedicated GUI instead, so you have some more options for making combinations / reserved slots without it being confusing like they are today. There is a rough version of the augment station block in the experimental branch if you want to look at it.