So I've ask around in game about bst pet exp penalties and been getting different answers. Some say it exist, but only apply to mobs that are higher than easy prey to bst, another say the penalty is always on doesn't matter the pet lv, and one person tells me that the exp penalty doesnt exist. Not sure are they referring when bst solo or party. Can I get some clarification?

In pt or solo, as long as you use a jug or even match or below pet there is no penalty. Xp is calculated based on the highest lvl therefore if you have a pet that is 1-2 lvls higher such as a T, then the xp is based on that being the highest lvl in the group.

Mickei, 75 BST