[Xrystal]

Originally Posted by SDPhantom MERCHANT_SHOW doesn't seem to be used by the retail client anymore and has been replaced with PLAYER_INTERACTION_MANAGER_FRAME_SHOW with the value of Enum.PlayerInteractionType.Merchant. This then calls MerchantFrame_MerchantShow(). MERCHANT_SHOW may still fire, but I'm getting a whiff of deprecation here.

You could be right there.
When the time comes / or if Hubb feels like making the addon somewhat future proof now, they might be able to replace the MERCHANT_SHOW event check to that PLAYER_INTERACTION_MANAGER_FRAME_SHOW event and check for that value you mentioned before continuing on with the rest of the functionality.