Assurance

https://rpgbot.net/p2/characters/assurance/

https://www.reddit.com/r/Pathfinder2e/comments/mgha30/comparison_between_assurance_and_recall_knowledge/

https://www.reddit.com/r/Pathfinder2e/comments/d16m88/does_assurance_work_the_way_i_think_it_does/

You are correct. However, it also doesn't take any penalties, so you can be at -10 MAP and use assurance to trip somebody or whatever and still have a shot.

https://paizo.com/threads/rzs42z19&page=1?Assurance-Athletics-and-Actual-Play

I will talk about my experiencie as a GM with a monk player who got assurance athletics.

Assurance athletics can be used as a focused Recall knowledge. You can use your 3rd action against the opponent, targeting fortitude or reflex, and you will get to know the range of the save.

For example, if you do a trip action, you are Expert Athl. at lvl 3, the check is 17. If you don´t succeed, you know he has 7 < Ref < 17, if you succed you know Ref < 7 . It can be valuable information for future encounters with that criature, for the next turn if you want to try without assurance, or for the other players to use their skills/spells against him. You can even spend to 2 actions in a turn getting this information for Ref and Fort saves.

https://paizo.com/threads/rzs43eo1&page=1?Assurance-just-seemsbad

Assurance cheese - Forensic medicine investigator, assurance medicine, Dump wisdom.

Normally 8 wis means you're not gonna be a good non-magic healer.
But expert at 2nd, Assurance doesn't add stat mods even if it's a penalty, free healz. Loads of skill feats to improve what you can do with medicine while not needing to actually increase your wisdom.

Assurance is one of my favorite Skill Feats in Pathfinder Second Edition.

Pros:

• Ignores penalties, like Multiple Attack Penalties (MAP), when making combat manuevers.
• Guarantees successes against enemies lower than your level; it can also be useful at equal or even higher levels if you're able to debuff the enemy.
  • Powergaming Warning: You can stat check enemies with an Assurance (Athletics) attack to learn about their Reflex or Fortitude saves
• Extremely effective at levels 7 and 8.
• Counter intuitive but it's potentially more useful to shore up skills where you have a low ability score modifier.
• Probably most beneficial with Medicine checks where the standard DC doesn't change and guarantees successes at level 3 or later (even with -1 or +0 WIS).

Understanding the math for it:

DC By Level

Ideally, you want the level to be less than or equal to your Assurance level.

Assurance no longer works with level 19 checks.