Game: 107137777, Tokyo. Turn 5
Game had Death Card, and Enhance. (and Villa, as well, in the kingdom)
I bought a Death Card, specifically to combine with Enhance.
DC: "You MAY trash this (or Action still in hand) for +5 coins."
Enhance: "You MAY trash a non-Victory card. Get a card up to +2 more in value."
On Turn 5, I had my chance. Used Enhance to trash Death Card. I'd obviously get a replacement card up to 6 in value. And I did get this. BUT...according to the wording on Death Card, I should also have received +5. Now, normally at this stage of the game, getting +5 would be meaningless (since I had already used my Buy for this turn). But in a game with Villa, I should have been able to gain Villa from Enhance--which gets me back to my Action stage, while also giving me that +5. I did try this, but never could get the 5 coins promised by the wording of Death Card...so I used Undo and used Enhance to instead get a Margrave. [And, of course, in any game that allows for plus-Buys, this combo could be very useful for a player who had accumulated additional buys in her or his turn.]
Nothing in the DC wording suggests that this combo would not work. Nothing about the DC card needing to be trashed during one's Action phase, for example.
Is this a bug? Or is it actually expected behavior?