Mixing the Spell Storing WSA with the Splinter Bolts could be a lot of fun, as you could turn any level 3 or lower spell in a 30ft cone. Furthermore, if your crossbow has Splitting you are also getting the effect twinned. Even without abusing this, you could use some damage spells to help with the low damage output that ranged weapons have in general.

The only downside is that the Spell Storing would have to go in the bolts, so you are paying an extra 80gp on top the cost of the bolt for every shot you make (less if you craft them yourself, obviously), but you end with a magic crossbow shotgun.

PS: The 1st level infusion Personal Weapon Augmentation can also give Spell Storing to a bolt, so if you go the artificer route you'll get to save a few bolts per day, if you time your castings right.