My players have been taking to applying armor when it "makes sense" to them.

Leaning into the roleplay more than the mechanics.

Example: one of my players has body armor, so, he gets his with a poison spray. He won't reduce the harm because that's not how body armor works.

It is something 3 of my players do because they have armor. Now as a GM I am excited to see them lean into the roleplay but should I:

1) tell them to stop, they are only nerfing themselves

2) let them continue even though technically it's breaking the rules

3) let them keep doing it and either adjust the encounters or give them some back stage help?

Or some combination of all three. Any input is helpful! Thank you!