When temp closing locations, one of the checks was a Fortitude check and Merisiel had both the Amulet of Fortitude and the Merchant at another location.  The game, while letting people spend blessings on the check all day long, does not allow me to utilize the Merchant's ability to give a card.  I should be able to discard the Merchant and pass the Amulet to the closing character where they could use the Amulet to pass the check.

If you're talking about the point in time where, after defeating a Henchman,  "Close Location" appeared, and you pressed 'Yes"- this is too late, you can't use the Merchant now, and you should've used it earlier (before your closing character explored).

 

However, I think there's an issue with the 'Close location?" when you empty a location deck - the prompt will appear immediately, and you can either accept it (at which point it would be too late to play the Merchant), or forfeit the opportunity altogether. And I don't think you would be allowed to exchange cards before selecting an answer to the prompt.

The correct behaviour would be that after you encounter the last card in a deck, you have opportunity to play cards and powers (including Merchant), before attempting a 'Close Location'.

 

Basically, the empty location 'Close?' prompt should be an 'End of Turn Action", while currently it's an 'immediately' action after you encounter the last card (i.e. you can't play cards between the encounter and the prompt). Even more egregious is that  if you fail to close, for you next turn a this location the prompt will become 'Start of Turn' action (so you can't do anything before you accept or forfeit the closing opportunity)