One other general feature of acrobatics which is easy to overlook since it's just a single sentence is that you can use your acrobatics proficiency in place of your unarmed attack proficiency when you use the Escape action. This makes acrobatics one of the most reliable ways to escape from being grappled or immobilized if your unarmed proficiency doesn't scale beyond expert (especially if you take the Acrobat archetype).
One other general feature of acrobatics which is easy to overlook since it's just a single sentence is that you can use your acrobatics proficiency in place of your unarmed attack proficiency when you use the Escape action. This makes acrobatics one of the most reliable ways to escape from being grappled or immobilized if your unarmed proficiency doesn't scale beyond expert (especially if you take the Acrobat archetype).
This is a fun series, very detailed.