It doesn't look like this is being applied to shrapnel hits. I had puncture resistance up, these are puncture crits, but no messaging saying the resistance has been applied.

A sudden booming of cannon fire erupts from the enemy merchant sloop!
* The shot crashes into the main deck, sending debris flying! A light hit!
The impact of the cannon fire sends shrapnel into the surroundings!
[SMR result: 108 (Open d100: 94)]
... the shrapnel heads right for you!
... 5 points of damage!
Minor puncture to the back.
Roundtime: 1 sec.

[SMR result: 106 (Open d100: 95)]
... the shrapnel heads right for you!
... 10 points of damage!
Strike to the chest breaks a rib!
Roundtime: 1 sec.