Please don't ruin the pure class by making the current live capstone only achievable as a PRE capstone. As the enhancements are listed here, it's not possible to recreate our current live artificer class:
Arcanotechnician should have the kind of capstone that increases spell casting ability, or works with the current, live capstone to allow meta-magics on clickies, spell power boosts, perhaps lore boosts or increased DCs.
Most of the ARCANOTECHNICIAN seems mediocre and bland. There's no spell lines to chose from; they are all boosted equally (that's fine in that it saves us APs, but it decreases customization). Enhancements for the pets are oddly woven in here, when they really should be part of the pet enhancements (and would make for interesting choices with pets rather than being laid overtop current choices). Lightning bolt doesn't make sense - I get that you're trying to give spell-using arties a powerful direct damage spell, but it would have been more interesting if arties had their own, new spell rather than having to copy one from wizards/sorcerers.