I've been playing ttrpgs for four decades now, and I love the creativity of 3rd party content and love to include it in games if it fits. I've done a good deal of freelance editing, balancing, and testing over the years. After the flood of poorly balanced 3rd party material that crashed in during the 3.0-3.5 DnD and Pf1 days I formed a system of Presentation of material, Ability to blend in established lore, Balance that i use to judge on now. I've liked other publications from this line and was looking forward to this one but couldn't extend those feelings to this material. This comes from making a few of these and also some characters with it as a dedication and ran them in some one shots of different levels. Here's what I found.
Presentation wise this would be 5 stars easy. I'd even give it 6. The way it blends the lore of Golarion id give it 5 too, but it falls so short in balance though which would make 2 in that reguard which is why overall I gave it a 3
This class is better than every other spellcasting class by far. Not only is it a full caster (Sorcerer Spellcasting with Wizard spells per day progression) it has the ability to compete with non fighter martials while being as good if not better then other casters at the same time, has strong defensive abilities, has very powerful Invocations (cantrips like Bards get but more than a few of these can compete with higher level spells ),, some of its class feats are above other sof similar levels, it is given loads of powerful free stuff from their Patron as they level, where similar classes would have the option to choose them as class feats as they level (like Sorcerer Bloodlines powers) This alone gives it bump of power like a Free Archetype built character but it's part of its class level progression.
It takes the cool stuff of a few classes, combines them and makes them better. It feels less of a balanced pf2e class and more of an upgraded 5e Warlock using pf2e system language. A little less of trying to transpose 5e Warlocks in its complete form to Pf2 and more focus on the spirit of the class would do wonders here. It does try to balance some things by needing to have a spell slot of that level available to use some abilities and Innovations but it has enough slots that's not really a trade off of note, I found others you need to have cast a spell from a slot before hand and those felt a bit more inline.
Things that might help:
Less is more here. Following established balance of other classes and not trying to shove everything in
Summoner spellcasting, not only does this cut down the number of available spells they have, it helps give balance to the very powerful Invocation cantrips and abilities they have access to and makes choosing to cast a slot or keep it for casting Invocations cantrips mean something.
Remove the freely given abilities and make them an option that becomes available as class feats as they level.
Where I might allow it: If I switched the spellcasting to Summoner Spell progression and then let it play in a game where I allow Free Archetype but it doesn't get to have one