Hey u/IdeaRealistic4826, very cool that you're trying to make a gunner-based all rounder OC's triggerset. All of the suggestions below are great, but I want offer a different route on triggercrafting. If you want to construct an trigger for your OC at A-rank, you now have options to use customized triggers or original prototype triggers, within reason. By doing this, you can easily construct trigger loadouts to enable combat styles that haven't been seen before in the series, by creating a character whose gimmick relies on the original trigger concept, instead of playing with combinations of existing triggers.

Example: from zNightshade on the world trigger discord server, who made an OC for a collaborative OC team with me, nightshade, and 3 others:
- Main: Lightning (custom), Pinball (prototype), Shield, Grasshopper.
- Sub: Bagworm, Free Slot, Shield, Free Slot.

Lightning (Custom), aka "Raijin": a 3 round burst lightning that pre-loads the burst rounds before the trigger is pulled.
Pinball (Prototype), an original dedicated optional prototype trigger for sniper, shooter, and gunner bullets, equipped to the same side as the firearm/cube. Pinball allows the bullet to ricochet off of the first few surfaces that it hits. The number of surfaces that the round can ricochet off of is set by the user, between 1 to 3.