With Jerold able to explore and focus on something that would make his partner stronger for the first time in a little while, he was very happy. The group also shared knowing looks. He had been the one scouting the paths with Devi the most. He had been the one showing off tracking skills and other related skills. But he had not been able to take a proper step forward.
Beyond this, there was the added effect that they knew that Jerold could be the perfect scouting assassin. He could sneak ahead and attack with poison invisibly due to his armored chaleons armor from which hid him.
This would be invaluable against the strongest opponents that they faced. While most stronger beasts had resistances to poison, Clark had just said that this extreme pin frog could be used to make the armored chameleon much stronger.